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/zombienet-tests/zombienet_bizinikiwi_tests.yml

@@ -0,0 +1,32 @@
+- job-name: "zombienet-bizinikiwi-0000-block-building"
+  test-definition: "block-building.zndsl"
+  local-dir: "./bizinikiwi/zombienet/0000-block-building"
+  runner-type: "default"
+  concurrency: 4
+  use-zombienet-sdk: false
+
+- job-name: "zombienet-bizinikiwi-0001-basic-warp-sync"
+  test-definition: "test-warp-sync.zndsl"
+  local-dir: "./bizinikiwi/zombienet/0001-basic-warp-sync"
+  runner-type: "default"
+  concurrency: 4
+  use-zombienet-sdk: false
+
+# TODO: Disabled, fails 1 in 50 runs
+- job-name: "zombienet-bizinikiwi-0002-validators-warp-sync"
+  test-definition: "test-validators-warp-sync.zndsl"
+  local-dir: "./bizinikiwi/zombienet/0002-validators-warp-sync"
+  runner-type: "default"
+  concurrency: 4
+  use-zombienet-sdk: false
+  additional-setup: |
+    cp --remove-destination ./bizinikiwi/zombienet/0001-basic-warp-sync/chain-spec.json ./bizinikiwi/zombienet/0002-validators-warp-sync
+
+- job-name: "zombienet-bizinikiwi-0003-block-building-warp-sync"
+  test-definition: "test-block-building-warp-sync.zndsl"
+  local-dir: "./bizinikiwi/zombienet/0003-block-building-warp-sync"
+  runner-type: "default"
+  concurrency: 4
+  use-zombienet-sdk: false
+  additional-setup: |
+    cp --remove-destination ./bizinikiwi/zombienet/0001-basic-warp-sync/chain-spec.json ./bizinikiwi/zombienet/0003-block-building-warp-sync