feat: err on failed to open region

[fengjiachun]

I hereby agree to the terms of the GreptimeDB CLA

What's changed and what's your intention?

As the title said.

Checklist

• I have written the necessary rustdoc comments.
• I have added the necessary unit tests and integration tests.

Refer to a related PR or issue link (optional)

[codecov]

Codecov Report

Merging #2442 (0e4a3d5) into develop (5805e8d) will decrease coverage by 0.06%.
Report is 4 commits behind head on develop.
The diff coverage is 100.00%.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #2442      +/-   ##
===========================================
- Coverage    77.70%   77.65%   -0.06%     
===========================================
  Files          730      730              
  Lines       115885   115911      +26     
===========================================
- Hits         90047    90006      -41     
- Misses       25838    25905      +67