disttask: replace manually mock with gomock

.github/licenserc.yml

@@ -48,4 +48,5 @@ header:
     - "build/image/.ci_bazel"
     - "**/OWNERS"
     - "OWNERS_ALIASES"
+    - "disttask/framework/mock/*_mock.go"
   comment: on-failure

Makefile

@@ -380,6 +380,9 @@ mock_lightning:
 	@mockgen -package mocklocal github.com/pingcap/tidb/br/pkg/lightning/backend/local DiskUsage,TiKVModeSwitcher > br/pkg/mock/mocklocal/local.go
 	@mockgen -package mock github.com/pingcap/tidb/br/pkg/utils TaskRegister > br/pkg/mock/task_register.go
 
+gen_mock:
+	@mockgen -package mock github.com/pingcap/tidb/disttask/framework/scheduler TaskTable,SubtaskExecutor,Pool,Scheduler,InternalScheduler > disttask/framework/mock/scheduler_mock.go
+
 # There is no FreeBSD environment for GitHub actions. So cross-compile on Linux
 # but that doesn't work with CGO_ENABLED=1, so disable cgo. The reason to have
 # cgo enabled on regular builds is performance.

disttask/framework/mock/BUILD.bazel

@@ -0,0 +1,12 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "mock",
+    srcs = ["scheduler_mock.go"],
+    importpath = "github.com/pingcap/tidb/disttask/framework/mock",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//disttask/framework/proto",
+        "@org_uber_go_mock//gomock",
+    ],
+)