Fix CI: use git reset --hard for reliable base commit restore

The previous approach using git reset HEAD~ followed by git restore .
wasn't reliably restoring the package.json to the base commit state,
causing "Command not found" errors when trying to run
generate-webpack-stats-file.

Using --hard ensures all tracked files are forcefully reset to the
base commit state. Also added --force to yarn install to ensure a
clean reinstall after the reset.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.github/workflows/pull-request-commit.yml

@@ -74,13 +74,12 @@ jobs:
       - name: Restore to base commit
         if: ${{ !steps.get-base-stats.outputs.cache-hit }}
         run: |
-          git reset HEAD~
-          git restore .
+          git reset --hard HEAD~
 
       - name: 🔦 Generate stats file from base commit
         if: ${{ !steps.get-base-stats.outputs.cache-hit }}
         run: |
-          yarn install
+          yarn install --force
           yarn intl:build
           yarn generate-webpack-stats-file
           mv stats.json stats-base.json