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/scripts/deny-git-deps.py

@@ -0,0 +1,49 @@
+"""
+Script to deny Git dependencies in the Cargo workspace. Can be passed one optional argument for the
+root folder. If not provided, it will use the cwd.
+
+## Usage
+	python3 .github/scripts/deny-git-deps.py pezkuwi-sdk
+"""
+
+import os
+import sys
+
+from cargo_workspace import Workspace, DependencyLocation
+
+# Some crates are allowed to have git dependencies until we fix them.
+ALLOWED_GIT_DEPS = {
+	'subwasmlib': ['pezkuwi-zombienet-sdk-tests'],
+}
+
+root = sys.argv[1] if len(sys.argv) > 1 else os.getcwd()
+workspace = Workspace.from_path(root)
+errors = []
+
+def check_dep(dep, used_by):
+	if dep.location != DependencyLocation.GIT:
+		return
+
+	if used_by in ALLOWED_GIT_DEPS.get(dep.name, []):
+		print(f'🤨 Ignoring git dependency {dep.name} in {used_by}')
+	else:
+		errors.append(f'🚫 Found git dependency {dep.name} in {used_by}')
+
+# Check the workspace dependencies that can be inherited:
+for dep in workspace.dependencies:
+	check_dep(dep, "workspace")
+
+	if workspace.crates.find_by_name(dep.name):
+		if dep.location != DependencyLocation.PATH:
+			errors.append(f'🚫 Workspace must use path to link local dependency {dep.name}')
+
+# And the dependencies of each crate:
+for crate in workspace.crates:
+	for dep in crate.dependencies:
+		check_dep(dep, crate.name)
+
+if errors:
+	print('❌ Found errors:')
+	for error in errors:
+		print(error)
+	sys.exit(1)