changefeedccl: Remove skipped tests that decayed over time

Remove
Fixes cockroachdb#32232
Remove TestChangefeedNodeShutdown.  This test has been disabled since
2018; Other tests exist (e.g. `TestChangefeedHandlesDrainingNodes`) that verify
restart behavior.

Fixes cockroachdb#51842
Remove BenchmarkChangefeedTicks benchmark.  This benchmark has been
skipped since 2019.  Attempts could be made to revive it; however, this
benchmark had a lot of code, which accomplished questionable goals.
The benchmark itself was unrepresentative (by using dependency
injection), too small to be meaningful (1000 rows), and most likely
would be too noise and inconclusive.  We have added other micro
benchmarks over time; and we conduct large scale testing, including
with roachtests.

Release note: None

pkg/ccl/changefeedccl/BUILD.bazel

@@ -182,7 +182,6 @@ go_test(
     srcs = [
         "alter_changefeed_test.go",
         "avro_test.go",
-        "bench_test.go",
         "changefeed_test.go",
         "csv_test.go",
         "encoder_test.go",
@@ -214,8 +213,6 @@ go_test(
         "//pkg/ccl/changefeedccl/changefeedbase",
         "//pkg/ccl/changefeedccl/changefeedpb",
         "//pkg/ccl/changefeedccl/kvevent",
-        "//pkg/ccl/changefeedccl/kvfeed",
-        "//pkg/ccl/changefeedccl/schemafeed",
         "//pkg/ccl/kvccl/kvtenantccl",
         "//pkg/ccl/multiregionccl",
         "//pkg/ccl/multiregionccl/multiregionccltestutils",
@@ -224,7 +221,6 @@ go_test(
         "//pkg/ccl/utilccl",
         "//pkg/cloud",
         "//pkg/cloud/impl:cloudimpl",
-        "//pkg/gossip",
         "//pkg/internal/sqlsmith",
         "//pkg/jobs",
         "//pkg/jobs/jobspb",
@@ -308,7 +304,6 @@ go_test(
         "//pkg/util/timeutil",
         "//pkg/util/timeutil/pgdate",
         "//pkg/util/uuid",
-        "//pkg/workload",
         "//pkg/workload/bank",
         "//pkg/workload/ledger",
         "//pkg/workload/workloadsql",