Catch more SSR issues and improve compat tests (#353)

This will cause the build to fail, as this will catch an SSR issue, which will be fixed after merging #369

.github/workflows/compatibility-tests.yml

@@ -42,4 +42,9 @@ jobs:
             ${{ runner.os }}-${{ matrix.node-version }}-yarn-
 
       - run: yarn install
-      - run: yarn test:compatibility:ci
+      # This will test whether `npm install`/`yarn install` can actually run on each compatibility test fixture. See `compatibility-tests/README.md` for more info.
+      - run:
+          yarn workspace @theatre/compatibility-tests run install-fixtures
+          --verbose
+      # after that, we run the jest tests for each fixture
+      - run: yarn test:compat