chore(perf): Pre-allocate where possible (enable prealloc linter) (#88952)

* chore(perf): Pre-allocate where possible (enable prealloc linter)

Signed-off-by: Dave Henderson <dave.henderson@grafana.com>

* fix TestAlertManagers_buildRedactedAMs

Signed-off-by: Dave Henderson <dave.henderson@grafana.com>

* prealloc a slice that appeared after rebase

Signed-off-by: Dave Henderson <dave.henderson@grafana.com>

---------

Signed-off-by: Dave Henderson <dave.henderson@grafana.com>

pkg/plugins/manager/loader/angular/angularinspector/angularinspector_test.go

@@ -93,6 +93,8 @@ func TestDefaultStaticDetectorsInspector(t *testing.T) {
 		plugin *plugins.Plugin
 		exp    bool
 	}
+
+	//nolint:prealloc // just a test, and it'd require too much refactoring to preallocate
 	var tcs []tc
 
 	// Angular imports