Remove some log noise in pause and abort handling

[cicdw]

Two things:

• our exception types have no repr/str of value; f"{Pause()}" prints an empty string, so I removed this from the log
• we log "unexpected exception" when catching exceptions that are more expected than unexpected; we have special handling for these exception types so shouldn't say they were unexpected

Closes #16915

[codspeed-hq]

CodSpeed Performance Report

Merging #17014 will not alter performance

_{Comparing improve-pause-abort-error-handling (641e46e) with main (750b9ce)}

Summary

✅ 2 untouched benchmarks