feat: Add rebrand CI/CD workflows to main branch

- Add 72 rebrand workflow files (polkadot→pezkuwi, substrate→bizinikiwi, cumulus→pezcumulus)
- Add GitHub actions, issue templates, and configs
- Removed unnecessary workflows (fork-sync, gitspiegel, upstream-tracker, sync-templates, backport)
- Renamed zombienet test files to match new naming convention

.github/workflows/reusable-isdraft.yml

@@ -0,0 +1,16 @@
+# The workflow is not part of reusable-preflight.yml to allow testing CI in draft.
+
+name: Preflight isdraft
+
+on:
+  workflow_call:
+    # Map the workflow outputs to job outputs
+
+jobs:
+  isdraft:
+    runs-on: ubuntu-latest
+    if: github.event.pull_request.draft == false || contains(github.event.pull_request.labels.*.name, 'A5-run-CI')
+    steps:
+      - name: echo test
+        shell: bash
+        run: echo "PR is not draft, starting CI"