Make CNI tests independent with continue-on-error

- Add fail-fast: false to CNI matrix strategy
- Add continue-on-error: true to check_cni job
- Update .gitignore to exclude secret.yaml

This ensures that if one CNI test fails, the other continues running,
and the overall workflow doesn't fail due to CNI test failures.

Author: fjammes

.github/workflows/e2e.yml

@@ -10,8 +10,10 @@ jobs:
     strategy:
       matrix:
         cni: [calico, cilium]
+      fail-fast: false
     name: Check CNI install
     runs-on: ubuntu-22.04
+    continue-on-error: true
     steps:
       - uses: actions/setup-go@v3
         with:

.gitignore

@@ -1,3 +1,4 @@
 /.claude
 /ktbx
 /.ktbx
+/secret.yaml