Remove two unused dependencies

- @actions/core was used when the @hypothesis/frontend-shared package was
  part of the client repo.
- postcss-url was used prior to the introduction of
  @hypothesis/frontend-build

package.json

@@ -8,7 +8,6 @@
   "repository": "hypothesis/client",
   "dependencies": {},
   "devDependencies": {
-    "@actions/core": "^1.2.6",
     "@babel/core": "^7.1.6",
     "@babel/preset-env": "^7.1.6",
     "@babel/preset-react": "^7.0.0",
@@ -71,7 +70,6 @@
     "mustache-express": "^1.3.0",
     "npm-packlist": "^3.0.0",
     "postcss": "^8.0.3",
-    "postcss-url": "^10.0.0",
     "preact": "^10.4.0",
     "prettier": "2.4.1",
     "puppeteer": "^11.0.0",

yarn.lock

@@ -2,20 +2,6 @@
 # yarn lockfile v1
 
 
-"@actions/core@^1.2.6":
-  version "1.6.0"
-  resolved "https://registry.yarnpkg.com/@actions/core/-/core-1.6.0.tgz#0568e47039bfb6a9170393a73f3b7eb3b22462cb"
-  integrity sha512-NB1UAZomZlCV/LmJqkLhNTqtKfFXJZAUPcfl/zqG7EfsQdeUJtaWO98SGbuQ3pydJ3fHl2CvI/51OKYlCYYcaw==
-  dependencies:
-    "@actions/http-client" "^1.0.11"
-
-"@actions/http-client@^1.0.11":
-  version "1.0.11"
-  resolved "https://registry.yarnpkg.com/@actions/http-client/-/http-client-1.0.11.tgz#c58b12e9aa8b159ee39e7dd6cbd0e91d905633c0"
-  integrity sha512-VRYHGQV1rqnROJqdMvGUbY/Kn8vriQe/F9HR2AlYHzmKuM/p3kjNuXhmdBfcVgsvRWTz5C5XW5xvndZrVBuAYg==
-  dependencies:
-    tunnel "0.0.6"
-
 "@babel/code-frame@7.12.11":
   version "7.12.11"
   resolved "https://registry.yarnpkg.com/@babel/code-frame/-/code-frame-7.12.11.tgz#f4ad435aa263db935b8f10f2c552d23fb716a63f"
@@ -2451,11 +2437,6 @@ css-what@2.1:
   resolved "https://registry.yarnpkg.com/css-what/-/css-what-2.1.3.tgz#a6d7604573365fe74686c3f311c56513d88285f2"
   integrity sha512-a+EPoD+uZiNfh+5fxw2nO9QwFa6nJe2Or35fGY6Ipw1R3R4AGz1d1TEZrCegvw2YTmZ0jXirGYlzxxpYSHwpEg==
 
-cuint@^0.2.2:
-  version "0.2.2"
-  resolved "https://registry.yarnpkg.com/cuint/-/cuint-0.2.2.tgz#408086d409550c2631155619e9fa7bcadc3b991b"
-  integrity sha1-QICG1AlVDCYxFVYZ6fp7ytw7mRs=
-
 custom-event@~1.0.0:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/custom-event/-/custom-event-1.0.1.tgz#5d02a46850adf1b4a317946a3928fccb5bfd0425"
@@ -4935,7 +4916,7 @@ make-dir@^2.1.0:
     pify "^4.0.1"
     semver "^5.6.0"
 
-make-dir@^3.0.0, make-dir@~3.1.0:
+make-dir@^3.0.0:
   version "3.1.0"
   resolved "https://registry.yarnpkg.com/make-dir/-/make-dir-3.1.0.tgz#415e967046b3a7f1d185277d84aa58203726a13f"
   integrity sha512-g3FeP20LNwhALb/6Cz6Dd4F2ngze0jz7tbzrD2wAV+o9FeNHe4rL+yK2md0J/fiSf1sa1ADhXqi5+oVwOM/eGw==
@@ -5027,12 +5008,12 @@ mime@1.6.0:
   resolved "https://registry.yarnpkg.com/mime/-/mime-1.6.0.tgz#32cd9e5c64553bd58d19a568af452acff04981b1"
   integrity sha512-x0Vn8spI+wuJ1O6S7gnbaQg8Pxh4NNHb7KSINmEWKiPE4RKOplvijn+NkmYmmRgP68mc70j2EbeTFRsrswaQeg==
 
-mime@^2.5.2, mime@~2.5.2:
+mime@^2.5.2:
   version "2.5.2"
   resolved "https://registry.yarnpkg.com/mime/-/mime-2.5.2.tgz#6e3dc6cc2b9510643830e5f19d5cb753da5eeabe"
   integrity sha512-tqkh47FzKeCPD2PUiPB6pkbMzsCasjxAfC62/Wap5qrUWcb+sFasXUC5I3gYM5iBM8v/Qpn4UK0x+j0iHyFPDg==
 
-minimatch@3.0.4, minimatch@^3.0.4, minimatch@~3.0.4:
+minimatch@3.0.4, minimatch@^3.0.4:
   version "3.0.4"
   resolved "https://registry.yarnpkg.com/minimatch/-/minimatch-3.0.4.tgz#5166e286457f03306064be5497e8dbb0c3d32083"
   integrity sha512-yJHVQEhyqPLUTgt9B83PXu6W3rx4MvvHvSUvToogpwoGDOUQ+yDrR0HRot+yOCdCO7u4hX3pWft6kWBBcqh0UA==
@@ -5714,16 +5695,6 @@ posix-character-classes@^0.1.0:
   resolved "https://registry.yarnpkg.com/posix-character-classes/-/posix-character-classes-0.1.1.tgz#01eac0fe3b5af71a2a6c02feabb8c1fef7e00eab"
   integrity sha1-AerA/jta9xoqbAL+q7jB/vfgDqs=
 
-postcss-url@^10.0.0:
-  version "10.1.3"
-  resolved "https://registry.yarnpkg.com/postcss-url/-/postcss-url-10.1.3.tgz#54120cc910309e2475ec05c2cfa8f8a2deafdf1e"
-  integrity sha512-FUzyxfI5l2tKmXdYc6VTu3TWZsInayEKPbiyW+P6vmmIrrb4I6CGX0BFoewgYHLK+oIL5FECEK02REYRpBvUCw==
-  dependencies:
-    make-dir "~3.1.0"
-    mime "~2.5.2"
-    minimatch "~3.0.4"
-    xxhashjs "~0.2.2"
-
 postcss-value-parser@^4.1.0:
   version "4.1.0"
   resolved "https://registry.yarnpkg.com/postcss-value-parser/-/postcss-value-parser-4.1.0.tgz#443f6a20ced6481a2bda4fa8532a6e55d789a2cb"
@@ -6991,11 +6962,6 @@ tslib@^1.9.3:
   resolved "https://registry.yarnpkg.com/tslib/-/tslib-1.14.1.tgz#cf2d38bdc34a134bcaf1091c41f6619e2f672d00"
   integrity sha512-Xni35NKzjgMrwevysHTCArtLDpPvye8zV/0E4EyYn43P7/7qvQwPh9BGkHewbMulVntbigmcT7rdX3BNo9wRJg==
 
-tunnel@0.0.6:
-  version "0.0.6"
-  resolved "https://registry.yarnpkg.com/tunnel/-/tunnel-0.0.6.tgz#72f1314b34a5b192db012324df2cc587ca47f92c"
-  integrity sha512-1h/Lnq9yajKY2PEbBadPXj3VxsDDu844OnaAo52UVmIzIvwwtBPIuNvkjuzBlTWpfJyUbG3ez0KSBibQkj4ojg==
-
 type-check@^0.4.0, type-check@~0.4.0:
   version "0.4.0"
   resolved "https://registry.yarnpkg.com/type-check/-/type-check-0.4.0.tgz#07b8203bfa7056c0657050e3ccd2c37730bab8f1"
@@ -7425,13 +7391,6 @@ xtend@~4.0.0, xtend@~4.0.1:
   resolved "https://registry.yarnpkg.com/xtend/-/xtend-4.0.2.tgz#bb72779f5fa465186b1f438f674fa347fdb5db54"
   integrity sha512-LKYU1iAXJXUgAXn9URjiu+MWhyUXHsvfp7mcuYm9dSUKK0/CjtrUwFAxD82/mCWbtLsGjFIad0wIsod4zrTAEQ==
 
-xxhashjs@~0.2.2:
-  version "0.2.2"
-  resolved "https://registry.yarnpkg.com/xxhashjs/-/xxhashjs-0.2.2.tgz#8a6251567621a1c46a5ae204da0249c7f8caa9d8"
-  integrity sha512-AkTuIuVTET12tpsVIQo+ZU6f/qDmKuRUcjaqR+OIvm+aCBsZ95i7UVY5WJ9TMsSaZ0DA2WxoZ4acu0sPH+OKAw==
-  dependencies:
-    cuint "^0.2.2"
-
 y18n@^3.2.1:
   version "3.2.2"
   resolved "https://registry.yarnpkg.com/y18n/-/y18n-3.2.2.tgz#85c901bd6470ce71fc4bb723ad209b70f7f28696"