.github/workflows: use CHATOPS_TOKEN for coverage comments

The default GITHUB_TOKEN has restricted permissions on fork PRs and
cannot post comments even with pull-requests: write permission. This
causes the coverage workflow to fail with "Resource not accessible by
integration" when trying to comment on PRs from forks.

Use CHATOPS_TOKEN instead, following the same pattern used in
slash.yml for fork PR interactions.

Fixes the error: GraphQL: Resource not accessible by integration (addComment)

Signed-off-by: Vincent Demeester <vdemeest@redhat.com>

Author: vdemeester

.github/workflows/go-coverage.yml

@@ -61,5 +61,6 @@ jobs:
         uses: fgrosse/go-coverage-report@8c1d1a09864211d258937b1b1a5b849f7e4f2682 # v1.2.0
         continue-on-error: true # This may fail if artifact on main branch does not exist (first run or expired)
         with:
+          token: ${{ secrets.CHATOPS_TOKEN }}
           coverage-artifact-name: "code-coverage"
           coverage-file-name: "coverage.txt"