ci: Run minimal/maximal version tests in the 'tests' job (#455)

By running fewer jobs we should need fewer workers and burn up less CPU
time, and hopefully spend less time waiting for jobs to launch. Also, at
least some build products should be reusable between these tests.

.github/workflows/tests.yml

@@ -117,47 +117,20 @@ jobs:
       - name: Check clippy
         # TODO: Deny warnings
         run: cargo clippy --all-targets --all-features
+      - run: cargo update
+      - name: Test after cargo update
+        run: cargo test --workspace
+      - name: Downgrade to minimal versions
+        if: matrix.version == 'nightly'
+        run: cargo +nightly -Zdirect-minimal-versions update
+      - name: Test on minimal versions
+        if: matrix.version == 'nightly'
+        run: cargo test
       - name: Install locked
-        run: cargo install --locked --path .
+        run: cargo install --path . --locked
       - name: Install unlocked
         run: cargo install --path .
 
-  minimal-versions:
-    needs: [quick-test]
-    strategy:
-      matrix:
-        os: [macOS-latest, ubuntu-latest, windows-latest]
-    runs-on: ${{ matrix.os }}
-    steps:
-      - uses: actions/checkout@v4
-      - uses: dtolnay/rust-toolchain@nightly
-      - uses: Swatinem/rust-cache@v2
-      - run: cargo +nightly -Zdirect-minimal-versions update
-      - run: cargo build --all-targets
-      - uses: taiki-e/install-action@v2
-        name: Install nextest using install-action
-        with:
-          tool: nextest
-      - run: cargo test
-
-  # Run `cargo update` and check the tests still pass
-  maximal-versions:
-    needs: [quick-test]
-    strategy:
-      matrix:
-        os: [macOS-latest, ubuntu-latest, windows-latest]
-    runs-on: ${{ matrix.os }}
-    steps:
-      - uses: actions/checkout@v4
-      - uses: dtolnay/rust-toolchain@nightly
-      - uses: Swatinem/rust-cache@v2
-      - run: cargo update
-      - uses: taiki-e/install-action@v2
-        name: Install nextest using install-action
-        with:
-          tool: nextest
-      - run: cargo test
-
   tests-from-tarball:
     needs: [quick-test]
     strategy:
@@ -270,16 +243,7 @@ jobs:
           path: mutants.out
 
   overall-result:
-    needs:
-      [
-        quick-test,
-        test,
-        minimal-versions,
-        maximal-versions,
-        tests-from-tarball,
-        pr-mutants,
-        cargo-mutants,
-      ]
+    needs: [quick-test, test, tests-from-tarball, pr-mutants, cargo-mutants]
     runs-on: ubuntu-latest
     if: always()
     steps: