Don't run isolate tests in GitHub actions

.github/workflows/main.yml

@@ -9,7 +9,7 @@ env:
 jobs:
   moor:
     name: "moor package"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
 
     steps:
       # setup
@@ -29,15 +29,16 @@ jobs:
       # build, test and upload coverage
       - run: dart run build_runner build --delete-conflicting-outputs
         working-directory: moor
-      - run: dart --no-sound-null-safety test --coverage=coverage
+      - run: dart --no-sound-null-safety test --coverage=coverage -x background_isolate
         working-directory: moor
       - uses: actions/upload-artifact@v2
         with:
           name: moor-coverage-data
           path: moor/coverage/
+          retention-days: 1
 
   moor_generator:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
     # setup
     - uses: actions/checkout@v2
@@ -53,7 +54,7 @@ jobs:
       working-directory: moor_generator/
 
   sqlparser:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       # setup
       - uses: actions/checkout@v2
@@ -74,10 +75,11 @@ jobs:
         with:
           name: sqlparser-coverage-data
           path: sqlparser/coverage
+          retention-days: 1
 
   misc_integration_tests:
     name: "Integration tests"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
       - uses: cedx/setup-dart@v2
@@ -88,7 +90,7 @@ jobs:
       - run: tool/misc_integration_test.sh
 
   upload_coverage:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     needs: [moor, sqlparser]
     steps:
       - uses: actions/checkout@v2
@@ -96,6 +98,14 @@ jobs:
       - run: dart pub upgrade
         name: "Setup coverage processor"
         working-directory: extras/coverage_formatting
+      - uses: actions/download-artifact@v2
+        with:
+          name: moor-coverage-data
+          path: moor/coverage/
+      - uses: actions/download-artifact@v2
+        with:
+          name: sqlparser-coverage-data
+          path: sqlparser/coverage/
       - run: dart run extras/coverage_formatting/bin/coverage.dart
         name: "Format coverage from raw data"
       - uses: codecov/codecov-action@v1

moor/dart_test.yaml

@@ -1,5 +1,6 @@
 tags:
   integration:
+  background_isolate:
 
 platforms:
   - vm

moor/test/isolate_test.dart

@@ -28,7 +28,7 @@ void main() {
     }
 
     _runTests(spawnBackground, true);
-  });
+  }, tags: 'background_isolate');
 
   test('stream queries across isolates', () async {
     // three isolates:
@@ -59,7 +59,7 @@ void main() {
     writer.kill();
     await expectation;
     await moorIsolate.shutdownAll();
-  });
+  }, tags: 'background_isolate');
 
   test('errors propagate across isolates', () async {
     final isolate = await MoorIsolate.spawn(_backgroundConnection);
@@ -78,7 +78,7 @@ void main() {
 
     await db.close();
     await isolate.shutdownAll();
-  });
+  }, tags: 'background_isolate');
 }
 
 void _runTests(