backupccl: break dependency to testcluster

Noticed we were building testing library packages when building CRDB
binaries.

    $ bazel query "somepath(//pkg/cmd/cockroach-short, //pkg/testutils/testcluster)"
    //pkg/cmd/cockroach-short:cockroach-short
    //pkg/cmd/cockroach-short:cockroach-short_lib
    //pkg/ccl:ccl
    //pkg/ccl/backupccl:backupccl
    //pkg/testutils/testcluster:testcluster

Release note: None

pkg/ccl/backupccl/BUILD.bazel

@@ -33,7 +33,6 @@ go_library(
         "split_and_scatter_processor.go",
         "system_schema.go",
         "targets.go",
-        "testutils.go",
     ],
     embed = [":backupccl_go_proto"],
     importpath = "github.com/cockroachdb/cockroach/pkg/ccl/backupccl",
@@ -79,7 +78,6 @@ go_library(
         "//pkg/sql/catalog/descidgen",
         "//pkg/sql/catalog/descpb",
         "//pkg/sql/catalog/descs",
-        "//pkg/sql/catalog/desctestutils",
         "//pkg/sql/catalog/ingesting",
         "//pkg/sql/catalog/multiregion",
         "//pkg/sql/catalog/nstree",
@@ -111,10 +109,6 @@ go_library(
         "//pkg/sql/stats",
         "//pkg/sql/types",
         "//pkg/storage",
-        "//pkg/testutils",
-        "//pkg/testutils/serverutils",
-        "//pkg/testutils/sqlutils",
-        "//pkg/testutils/testcluster",
         "//pkg/util",
         "//pkg/util/admission",
         "//pkg/util/contextutil",
@@ -129,23 +123,19 @@ go_library(
         "//pkg/util/metric",
         "//pkg/util/mon",
         "//pkg/util/protoutil",
-        "//pkg/util/randutil",
         "//pkg/util/retry",
         "//pkg/util/span",
         "//pkg/util/stop",
         "//pkg/util/syncutil",
         "//pkg/util/timeutil",
         "//pkg/util/tracing",
         "//pkg/util/uuid",
-        "//pkg/workload/bank",
-        "//pkg/workload/workloadsql",
         "@com_github_cockroachdb_errors//:errors",
         "@com_github_cockroachdb_logtags//:logtags",
         "@com_github_gogo_protobuf//jsonpb",
         "@com_github_gogo_protobuf//types",
         "@com_github_kr_pretty//:pretty",
         "@com_github_robfig_cron_v3//:cron",
-        "@com_github_stretchr_testify//require",
     ],
 )
 
@@ -180,6 +170,7 @@ go_test(
         "show_test.go",
         "split_and_scatter_processor_test.go",
         "system_schema_test.go",
+        "utils_test.go",
     ],
     data = glob(["testdata/**"]) + ["//c-deps:libgeos"],
     embed = [":backupccl"],
@@ -271,6 +262,7 @@ go_test(
         "//pkg/util/timeutil",
         "//pkg/util/uuid",
         "//pkg/workload/bank",
+        "//pkg/workload/workloadsql",
         "@com_github_aws_aws_sdk_go//aws/credentials",
         "@com_github_cockroachdb_cockroach_go_v2//crdb",
         "@com_github_cockroachdb_datadriven//:datadriven",