[ci] Consolidate docs jobs (#7910)

We build docs in three different places, which is annoying to deal with, and it means we build docs two more times than necessary. Now, docs are built just once in the main Gradle workflow, with warnings promoted to errors, eliminating the need for the separate job in lint-format.yml. The uploaded docs artifact is then unpacked and commited to the GitHub Pages repo like normal.

.github/workflows/lint-format.yml

@@ -123,18 +123,3 @@ jobs:
           echo '' >> $GITHUB_STEP_SUMMARY
           echo '```' >> $GITHUB_STEP_SUMMARY
         if: ${{ failure() }}
-
-  documentation:
-    name: "Documentation"
-    runs-on: ubuntu-22.04
-    needs: [validation]
-    steps:
-      - uses: actions/checkout@v4
-        with:
-          fetch-depth: 0
-      - uses: actions/setup-java@v4
-        with:
-          distribution: 'temurin'
-          java-version: 21
-      - name: Build with Gradle
-        run: ./gradlew docs:zipDocs -PbuildServer -PdocWarningsAsErrors ${{ env.EXTRA_GRADLE_ARGS }}