- `./mvnw test ...` by its nature only runs unit tests, whose name is pattern of `*Test`, and it does never runs integration tests, whose name is patter of `IT*` or `*IT`, so in this PR we use `./mvnw clean test ...` to only run unit tests.
- `./mvnw integration-test ...` will run integration tests and unit tests, so we have `skipUTs` to control whether to skip the UT when running ITs, we already had this before.
  - As for ITs, we have two groups, one is normal tests without any `@Tag`s, the other one is slow integration tests, which is annotated with `@Tag("slow")`, so we divided the integration tests into two workflow jobs:
  - `./mvnw -DskipUTs=true clean integration-test -DexcludedGroups=slow ...` run the ITs but don't run the slow ITs and UTs, `-DexcludedGroups=slow` excludes tests annotated with `@Tag("slow")`
  - `./mvnw -DskipUTs=true clean integration-test -Dcheckstyle.skip -Dtest=${{ matrix.test.class }}` run the slow ITs (because `excludedGroups` is not set) one case at a time, by setting `-Dtest={{ class }}`, not run UTs,