ci: switch to latest LTS Ubuntu version

.github/workflows/patch.yml

@@ -10,7 +10,7 @@ on:
 
 jobs:
   test:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-latest
     timeout-minutes: 60
 
     name: Patch Test

.github/workflows/server-tests.yml

@@ -14,7 +14,7 @@ on:
 
 jobs:
   test:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-latest
     timeout-minutes: 60
 
     strategy:
@@ -113,7 +113,7 @@ jobs:
     name: Coverage Wrap Up
     needs: test
     container: python:3-slim
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-latest
     steps:
       - name: Clone
         uses: actions/checkout@v2

.github/workflows/translation_linter.yml

@@ -1,22 +0,0 @@
-name: Frappe Linter
-on:
-  pull_request:
-    branches:
-      - develop
-      - version-12-hotfix
-      - version-11-hotfix
-jobs:
-  check_translation:
-    name: Translation Syntax Check
-    runs-on: ubuntu-18.04
-    steps:
-    - uses: actions/checkout@v2
-    - name: Setup python3
-      uses: actions/setup-python@v1
-      with:
-        python-version: 3.6
-    - name: Validating Translation Syntax
-      run: |
-        git fetch origin $GITHUB_BASE_REF:$GITHUB_BASE_REF -q
-        files=$(git diff --name-only --diff-filter=d $GITHUB_BASE_REF)
-        python $GITHUB_WORKSPACE/.github/helper/translation.py $files

.github/workflows/ui-tests.yml

@@ -8,7 +8,7 @@ on:
 
 jobs:
   test:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-latest
     timeout-minutes: 60
 
     strategy: