CI: Split matrix between rspec and minitest

The codebase's CI executions for Minitest support have proven to be
fairly stable and predictable. Meanwhile the RSpec test harness is
flaky.

This commit splits out the test commands into separate CI matrix entries
to better understand the execution characteristics.

Author: seanpdoyle

.github/workflows/ci.yml

@@ -8,6 +8,9 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
+        test:
+          - "bin/rails test:all"
+          - "bundle exec rspec"
         driver:
           - "cuprite"
           - "playwright"
@@ -26,7 +29,7 @@ jobs:
       DRIVER: ${{ matrix.driver }}
       RAILS_VERSION: ${{ matrix.rails-version }}
 
-    name: ${{ format('Tests (Ruby {0}, Rails {1}, {2})', matrix.ruby-version, matrix.rails-version, matrix.driver) }}
+    name: ${{ format('Tests (Ruby {0}, Rails {1}, {2}, Driver {3})', matrix.ruby-version, matrix.rails-version, matrix.test, matrix.driver) }}
     runs-on: "ubuntu-latest"
 
     steps:
@@ -45,6 +48,12 @@ jobs:
         run: yarn install && yarn playwright install
 
       - run: bin/rails standard
-        if: matrix.ruby-version != 3.2
-      - run: bin/rails test:all
-      - run: bundle exec rspec
+      - run: ${{ matrix.test }}
+
+      - name: Keep screenshots from failed system tests
+        uses: actions/upload-artifact@v6
+        if: failure()
+        with:
+          name: screenshots
+          path: ${{ github.workspace }}/tmp/screenshots
+          if-no-files-found: ignore

Gemfile

@@ -17,6 +17,7 @@ end
 
 gem "rails", rails_constraint
 gem "rspec-rails"
+gem "minitest", "< 6"
 
 gem "puma"
 gem "standard", "~> 1.12"