When a test is cancelled due to `time_limit`, the error message is not clear

[vkarak]

Actually, the only information that can be found that the test was actually killed due to time limit is in the debug2 logs!

[2022-12-15T15:06:08] debug2: reframe: [S] local: Job 12649 timed out; kill it

We should make the reason clear in the failure description.