Python 3.9 (#2886)

* Python 3.9

* Fix lint

* fix lint

.github/workflows/builder.yml

@@ -35,7 +35,7 @@ on:
 env:
   BUILD_NAME: supervisor
   BUILD_TYPE: supervisor
-  WHEELS_TAG: 3.8-alpine3.13
+  WHEELS_TAG: 3.9-alpine3.13
 
 jobs:
   init:
@@ -71,7 +71,7 @@ jobs:
       - name: Check if requirements files changed
         id: requirements
         run: |
-          if [[ "${{ steps.changed_files.outputs.all }}" =~ requirements.txt ]]; then
+          if [[ "${{ steps.changed_files.outputs.all }}" =~ (requirements.txt|build.json) ]]; then
             echo "::set-output name=changed::true"
           fi
 

.github/workflows/ci.yaml

@@ -8,7 +8,7 @@ on:
   pull_request: ~
 
 env:
-  DEFAULT_PYTHON: 3.8
+  DEFAULT_PYTHON: 3.9
   PRE_COMMIT_HOME: ~/.cache/pre-commit
 
 jobs:
@@ -18,7 +18,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.8]
+        python-version: [3.9]
     name: Prepare Python ${{ matrix.python-version }} dependencies
     steps:
       - name: Check out code from GitHub
@@ -343,7 +343,7 @@ jobs:
     needs: prepare
     strategy:
       matrix:
-        python-version: [3.8]
+        python-version: [3.9]
     name: Run tests Python ${{ matrix.python-version }}
     steps:
       - name: Check out code from GitHub