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/actions/cargo-check-runtimes/action.yml

@@ -0,0 +1,22 @@
+name: 'cargo check runtimes'
+description: 'Runs `cargo check` for every directory in provided root.'
+inputs:
+  root:
+    description: "Root directory. Expected to contain several cargo packages inside."
+    required: true
+runs:
+  using: "composite"
+  steps:
+    - name: Check
+      shell: bash
+      run: |
+        mkdir -p ~/.forklift
+        cp .forklift/config.toml ~/.forklift/config.toml
+        cd ${{ inputs.root }}
+        for directory in $(echo */); do
+          echo "_____Running cargo check for ${directory} ______";
+          cd ${directory};
+          pwd;
+          SKIP_WASM_BUILD=1 forklift cargo check --locked;
+          cd ..;
+        done