Chore: Attempt to reduce flakiness in integration tests (#97247)

* sqlstore/sqlutil: set sync=OFF for sqlite in tests if wal=true

* testinfra: set max open/idle conn to 2 to match e2e tests

pkg/services/sqlstore/sqlutil/sqlutil.go

@@ -110,7 +110,8 @@ func sqLite3TestDB() (*TestDB, error) {
 
 	ret.ConnStr = "file:" + sqliteDb + "?cache=private&mode=rwc"
 	if os.Getenv("SQLITE_JOURNAL_MODE") != "false" {
-		ret.ConnStr += "&_journal_mode=WAL"
+		// For tests, set sync=OFF for faster commits. Reference: https://www.sqlite.org/pragma.html#pragma_synchronous.
+		ret.ConnStr += "&_journal_mode=WAL&_synchronous=OFF"
 	}
 	ret.Path = sqliteDb