client+server: cleanup GitHub actions workflow names

Also run unit test action on push

.github/workflows/build-containers.yml

@@ -1,7 +1,8 @@
-name: build-containers
+name: Build Docker containers
 on: [push]
 jobs:
   build-client:
+    name: Build and push client/ Docker container
     runs-on: ubuntu-latest
     steps:
       - name: Login to Docker Hub
@@ -53,6 +54,7 @@ jobs:
           ./client
 
   build-server:
+    name: Build and push server/ Docker container
     runs-on: ubuntu-latest
     steps:
       - name: Login to Docker Hub

.github/workflows/run-unit-tests.yml

@@ -1,16 +1,28 @@
-name: run-unit-tests
-on: [pull_request]
+name: Run unit tests
+on: [push, pull_request]
 jobs:
   test-server:
+    name: Run pytest for server/
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
         uses: actions/checkout@v2
 
+      - name: Set up Docker Buildx
+        id: buildx
+        uses: docker/setup-buildx-action@v1
+
       - name: Build test container
-        run: |
-          TAG=$(docker build --target testing -q ./server)
-          echo "image_tag=${TAG}" >> $GITHUB_ENV
+        run: >
+          docker buildx build --load
+          --platform linux/amd64 --target testing
+          -t test_container
+          ./server
 
       - name: Run unit tests
-        run: docker run --rm -t ${{ env.image_tag }} --color=no szurubooru/
+        run: >
+          docker run --rm -t test_container
+          --color=no
+          --cov-report=term-missing:skip-covered
+          --cov=szurubooru
+          szurubooru/

.pre-commit-config.yaml

@@ -83,17 +83,6 @@ repos:
         files: server/szurubooru/
         exclude: server/szurubooru/migrations/
         pass_filenames: false
-        stages: [push]
-
-    -   id: pytest-cov
-        name: pytest
-        entry: bash -c 'docker run --rm -t $(docker build --target testing -q server/) --cov-report=term-missing:skip-covered --cov=szurubooru szurubooru/'
-        language: system
-        types: [python]
-        files: server/szurubooru/
-        exclude: server/szurubooru/migrations/
-        pass_filenames: false
-        verbose: true
         stages: [manual]
 
 fail_fast: true