fix(ci): add --repo flag to gh commands in release-please workflow

gh CLI has no git repo context in the release-please job (no checkout
step), so it cannot auto-detect the repository. Adding --repo
$GITHUB_REPOSITORY to all three gh commands resolves the error:
'failed to run git: fatal: not a git repository'

Author: kellenmurphy

.github/workflows/release-please.yml

@@ -29,6 +29,6 @@ jobs:
               run: |
                   PR_NUMBER=$(echo '${{ steps.release.outputs.pr }}' | jq -r '.number')
                   PR_BRANCH=$(echo '${{ steps.release.outputs.pr }}' | jq -r '.headBranchName')
-                  gh workflow run ci.yml --ref "$PR_BRANCH"
-                  gh pr review "$PR_NUMBER" --approve --body "Approved by release-please automation."
-                  gh pr merge --auto --merge "$PR_NUMBER"
+                  gh workflow run ci.yml --ref "$PR_BRANCH" --repo "$GITHUB_REPOSITORY"
+                  gh pr review "$PR_NUMBER" --approve --body "Approved by release-please automation." --repo "$GITHUB_REPOSITORY"
+                  gh pr merge --auto --merge "$PR_NUMBER" --repo "$GITHUB_REPOSITORY"