Run GH actions on ubuntu-20.04

Signed-off-by: Tamal Saha <[email protected]>

.github/workflows/cherry-pick.yml

@@ -7,7 +7,7 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
 
     steps:
       - uses: actions/checkout@v1

.github/workflows/ci.yml

@@ -11,7 +11,7 @@ on:
 jobs:
   build:
     name: Build
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - name: Set up Go 1.19
         uses: actions/setup-go@v1

.github/workflows/release-tracker.yml

@@ -6,7 +6,7 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
 
     steps:
       - uses: actions/checkout@v1

.github/workflows/release.yml

@@ -8,7 +8,7 @@ on:
 jobs:
   build:
     name: Build
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - name: Check out code into the Go module directory
         uses: actions/checkout@v1