chore(ci): ubuntu version pinning to 20.04

.github/workflows/ci.yml

@@ -8,7 +8,7 @@ on:
 
 jobs:
   commit_lint:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
         with:
@@ -18,7 +18,7 @@ jobs:
           firstParent: true
   golangci:
     name: lint
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
       - name: Run golangci-lint
@@ -29,7 +29,7 @@ jobs:
           args: --timeout 5m --config .golangci.yml
   diff:
     name: diff
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
         with:

.github/workflows/e2e.yml

@@ -33,7 +33,7 @@ jobs:
       fail-fast: false
       matrix:
         k8s-version: ['v1.20.7', 'v1.21.2', 'v1.22.4', 'v1.23.6', 'v1.24.7', 'v1.25.3', 'v1.26.1']
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
         with:

.github/workflows/gosec.yml

@@ -6,7 +6,7 @@ on:
     branches: [ "*" ]
 jobs:
   tests:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     env:
       GO111MODULE: on
     steps:

.github/workflows/helm.yml

@@ -9,7 +9,7 @@ on:
 
 jobs:
   lint:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
         with:
@@ -69,7 +69,7 @@ jobs:
       #  if: steps.list-changed.outputs.changed == 'true'
   release:
     if: startsWith(github.ref, 'refs/tags/helm-v')
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
       - name: Publish Helm chart