GitHub Actions Cleanup (#1467)

Summary:
Pull Request resolved: https://github.com/facebook/yoga/pull/1467

1. Avoid reusing workflow names between validation and publish jobs, since they show up with the same UI when wanting to adhoc trigger a publish.
2. Merge SwiftPM checks into Validate Apple job
3. Merge remnants of website-next workflow into website workflow (and remove a redundant explicit build step already removed in one workflow)
4. Run more validation on push to release branch
5. Do not run website validation off of main, since it is only ever deployed from main branch

Reviewed By: cipolleschi

Differential Revision: D51236885

fbshipit-source-id: dd8165aa9871f173d8914f345569c6cde1edda72

.github/workflows/validate-website.yml

@@ -1,7 +1,9 @@
-name: Website
+name: Validate Website
 
 on:
   pull_request:
+    branches:
+      - main
   push:
     branches:
       - main
@@ -32,10 +34,20 @@ jobs:
       - name: Setup
         uses: ./.github/actions/setup-js
 
-      - name: Build Yoga
-        run: yarn build
-        working-directory: javascript
-
       - name: Build Website
         run: yarn build
         working-directory: website-next
+
+  typecheck:
+    name: Typecheck [Docusaurus]
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Setup
+        uses: ./.github/actions/setup-js
+
+      - name: yarn tsc
+        run: yarn tsc
+        working-directory: website-next