CI: Use Solidus' reusable GH workflow for testing

Instead of setting up all services and the matrix
in this extension we use the new reusable workflow
that handles this for us.

Needs solidusio/test-solidus-extension#3

Author: tvdeyen

.github/workflows/test.yml

@@ -16,48 +16,5 @@ permissions:
   contents: read
 
 jobs:
-  rspec:
-    name: Solidus ${{ matrix.solidus-branch }}, Rails ${{ matrix.rails-version }} and Ruby ${{ matrix.ruby-version }} on ${{ matrix.database }}
-    runs-on: ubuntu-24.04
-    strategy:
-      fail-fast: false
-      matrix:
-        rails-version:
-          - "7.2"
-          - "8.0"
-        ruby-version:
-          - "3.1"
-          - "3.4"
-        solidus-branch:
-          - "v4.4"
-          - "v4.5"
-          - "v4.6"
-        database:
-          - "postgresql"
-          - "mysql"
-          - "sqlite"
-        exclude:
-          - solidus-branch: "v4.5"
-            ruby-version: "3.1"
-          - solidus-branch: "v4.6"
-            ruby-version: "3.1"
-          - solidus-branch: "v4.4"
-            rails-version: "8.0"
-    env:
-      TEST_RESULTS_PATH: coverage/coverage.xml
-      CAPYBARA_JAVASCRIPT_DRIVER: selenium_headless
-    steps:
-      - uses: actions/checkout@v4
-      - name: Run extension tests
-        uses: solidusio/test-solidus-extension@main
-        with:
-          database: ${{ matrix.database }}
-          rails-version: ${{ matrix.rails-version }}
-          ruby-version: ${{ matrix.ruby-version }}
-          solidus-branch: ${{ matrix.solidus-branch }}
-      - name: Upload coverage reports to Codecov
-        uses: codecov/codecov-action@v5
-        continue-on-error: true
-        with:
-          token: ${{ secrets.CODECOV_TOKEN }}
-          files: ${{ env.TEST_RESULTS_PATH }}
+  Test:
+    uses: solidusio/test-solidus-extension/.github/workflows/test.yml@add-reusable-workflow