fix: pass only required secrets to build-instrumented workflow

Replace 'secrets: inherit' with explicit GITHUB_TOKEN secret to follow
security best practices. The build-instrumented-plugins.yaml workflow
only requires GITHUB_TOKEN for GHCR authentication.

Fixes GitHub security alert: githubactions:S7635

Author: gustavolira

.github/workflows/e2e-ocp-helm-pr.yaml

@@ -249,7 +249,8 @@ jobs:
     with:
       workspace: ${{ matrix.workspace }}
       pr-number: ${{ inputs.pr-number }}
-    secrets: inherit
+    secrets:
+      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
   e2e-test-with-coverage:
     needs: [detect-workspaces, build-instrumented]