chore: remove workflows for public mirror

.github/workflows/docker-base.yml

@@ -1,29 +0,0 @@
-name: "Validate Docker base image"
-on: 
-  workflow_dispatch:
-  pull_request:
-    paths:
-    - "Dockerfile.base"
-    - ".github/workflows/docker-base.yml"
-jobs:
-  build-and-test:
-    runs-on: ubuntu-latest
-    steps:
-    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
-    - name: "build and test"
-      run: |
-        set -e
-        IMG="test-base:$(head -c 8 /dev/urandom | xxd -p)"
-        docker build -t "$IMG" -f Dockerfile.base .
-
-        iptables_version=$(docker run --rm "$IMG" iptables --version)
-        if [[ "$iptables_version" != *"(legacy)"* ]]; then
-            echo "ERROR: Docker base image should contain legacy iptables; found ${iptables_version}"
-            exit 1
-        fi
-
-        ip6tables_version=$(docker run --rm "$IMG" ip6tables --version)
-        if [[ "$ip6tables_version" != *"(legacy)"* ]]; then
-            echo "ERROR: Docker base image should contain legacy ip6tables; found ${ip6tables_version}"
-            exit 1
-        fi