Chore: Bump Yarn (#4739)

Because:
- We were still on the classic version and that often causes issues for
contributors who are using a more up to date version of Yarn.

This commit:
- Bumps to the latest version of Yarn
- Amends the .gitignore file based on what Yarn recommends -
https://yarnpkg.com/getting-started/qa#which-files-should-be-gitignored

.github/workflows/ci.yml

@@ -29,7 +29,7 @@ jobs:
 
       - name: Install packages
         run: |
-          yarn install --pure-lockfile
+          yarn install
 
       - name: Run linters
         run: |
@@ -70,7 +70,7 @@ jobs:
 
       - name: Install packages
         run: |
-          yarn install --pure-lockfile
+          yarn install
 
       - name: Build assets
         run: |

.gitignore

@@ -44,11 +44,17 @@
 /public/packs
 /public/packs-test
 /node_modules
+
+
+# yarn -
+.pnp.*
+.yarn/*
+!.yarn/patches
+!.yarn/plugins
+!.yarn/releases
+!.yarn/sdks
+!.yarn/versions
 /yarn-error.log
-yarn-debug.log*
-.yarn-integrity
-.yarn/
-.yarnrc.yml
 
 # Spec example persistence / failure tracking
 /spec/examples.txt
@@ -61,4 +67,4 @@ yarn-debug.log*
 !/app/assets/builds/.keep
 
 # Ruby tool versions
-.tool-versions
+.tool-versions

.yarnrc.yml

@@ -0,0 +1,3 @@
+nodeLinker: node-modules
+
+yarnPath: .yarn/releases/yarn-4.4.0.cjs

package.json

@@ -45,5 +45,6 @@
     "eslint": "^8.57.0",
     "eslint-config-airbnb": "^19.0.4",
     "eslint-plugin-import": "^2.29.1"
-  }
+  },
+  "packageManager": "[email protected]"
 }