asim: extract assertions into its own package

Previously, simulation assertions resided within the tests package.

Another PR(cockroachdb#109316) is introducing assertion registration which enables
scheduled assertion checks to run as delayed events. Since these assertion
events require the assertion structs to conduct assertion checks, the event
package would have to depend on the test package. However, the test package
would also have to depend on the event package’s exported struct to initialize
structures for event generation, creating a circular dependency.

To address this issue, this patch moves the assertion component out of the test
package to its own package.

Note that this commit does not change any existing behavior, and the main
purpose is to make future commits cleaner.

See also: cockroachdb#109316
Part of: cockroachdb#106192
Release note: none

pkg/BUILD.bazel

@@ -1300,6 +1300,7 @@ GO_TARGETS = [
     "//pkg/kv/kvserver/allocator:allocator",
     "//pkg/kv/kvserver/apply:apply",
     "//pkg/kv/kvserver/apply:apply_test",
+    "//pkg/kv/kvserver/asim/assertion:assertion",
     "//pkg/kv/kvserver/asim/config:config",
     "//pkg/kv/kvserver/asim/event:event",
     "//pkg/kv/kvserver/asim/gen:gen",

pkg/kv/kvserver/asim/assertion/BUILD.bazel

@@ -0,0 +1,16 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "assertion",
+    srcs = ["assert.go"],
+    importpath = "github.com/cockroachdb/cockroach/pkg/kv/kvserver/asim/assertion",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//pkg/kv/kvserver/asim/history",
+        "//pkg/kv/kvserver/asim/metrics",
+        "//pkg/roachpb",
+        "//pkg/spanconfig/spanconfigtestutils",
+        "//pkg/util/log",
+        "@com_github_montanaflynn_stats//:stats",
+    ],
+)