feat: Vendor pezkuwi-subxt and pezkuwi-zombienet-sdk into monorepo

- Add pezkuwi-subxt crates to vendor/pezkuwi-subxt
- Add pezkuwi-zombienet-sdk crates to vendor/pezkuwi-zombienet-sdk
- Convert git dependencies to path dependencies
- Add vendor crates to workspace members
- Remove test/example crates from vendor (not needed for SDK)
- Fix feature propagation issues detected by zepter
- Fix workspace inheritance for internal dependencies
- All 606 crates now in workspace
- All 6919 internal dependency links verified correct
- No git dependencies remaining

vendor/pezkuwi-subxt/.github/workflows/validate-dependabot.yml

@@ -0,0 +1,14 @@
+name: Dependabot
+
+on:
+  pull_request:
+    paths:
+      - '.github/dependabot.yml'
+      - '.github/workflows/validate-dependabot.yml'
+jobs:
+  validate:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+      - uses: marocchino/validate-dependabot@v3
+        id: validate