Improve the collector github workflow (signalfx#1044)

* Optimize collector workflow to use a single 'update-collector' branch, preventing multiple PRs for different versions when only one is needed

* Apply 'Skip Changelog' label for the collector workflow since the automated release notes will handle this task

.github/workflows/update_collector.yaml

@@ -37,6 +37,9 @@ jobs:
           commit-message: Update collector version
           title: Update collector version to ${{ steps.update.outputs.LATEST_VER }}
           body: Use the new version of the collector
-          branch: "update-${{ steps.update.outputs.LATEST_VER }}"
+          branch: "update-collector"
+          # The "Skip Changelog" label is applied because the ci_scripts/chloggen-update.sh script
+          # will automatically add information about the collector when a release is created.
+          labels: ["Skip Changelog"]
           base: main
           delete-branch: true