chore(db): cleanup DB in tests and remove OpenTemp (#10282)

Filled up my tmpfs with test DBs when running benchmarks :)

internal/db/sqlite/db_mtimes_test.go

@@ -14,7 +14,7 @@ import (
 func TestMtimePairs(t *testing.T) {
 	t.Parallel()
 
-	db, err := OpenTemp()
+	db, err := Open(t.TempDir())
 	if err != nil {
 		t.Fatal()
 	}