ci: add target_commitish to correctly reference commit in prerelease tags

Author: LeoAnders

.github/workflows/prerelease.yml

@@ -99,6 +99,7 @@ jobs:
         uses: softprops/action-gh-release@v1
         with:
           tag_name: v${{ steps.set-version.outputs.version }}
+          target_commitish: ${{ github.sha }}
           prerelease: ${{ github.event_name != 'release' }}
           files: ${{ steps.set-version.outputs.name }}.vsix
           token: ${{ secrets.GITHUB_TOKEN }}