Adding a serialized test task

Under normal circumstances, `rake -m test` will parallelize not only the build task, but also the test task.
With this patch, `rake -m test:run:serial` will parallelize the build tasks, but the test tasks will be done one by one in sequence.

The name of the task to be added is as follows:

| tasks to be added     | corresponding exist tasks
| --------------------- | ----------------
| `test:run:serial`     | `test:run`
| `test:run:serial:bin` | `test:run:bin`
| `test:run:serial:lib` | `test:run:lib`

.github/workflows/build.yml

@@ -36,7 +36,7 @@ jobs:
       - name: Compiler version
         run: ${{ env.CC }} --version
       - name: Build and test
-        run: rake -m test:build && rake test:run
+        run: rake -m test:run:serial
 
   Windows-VC:
     runs-on: windows-2022
@@ -52,4 +52,4 @@ jobs:
         shell: cmd
         run: |
           call "C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
-          rake -m test:build && rake test:run
+          rake -m test:run:serial