fix(db): fix bugs based on sqlite date format difference from chrono

[boxbeam]

cc @liangfung

[wsxiaoys]

Please add a unit test to cover this situation.

[codecov]

Codecov Report

Attention: Patch coverage is 84.12698% with 10 lines in your changes are missing coverage. Please review.

Project coverage is 55.84%. Comparing base (fccd409) to head (6ad4c74).
Report is 2 commits behind head on main.

Files	Patch %	Lines
ee/tabby-db/src/lib.rs	86.66%	6 Missing ⚠️
ee/tabby-db/src/user_events.rs	0.00%	2 Missing ⚠️
ee/tabby-db/src/github_repository_provider.rs	85.71%	1 Missing ⚠️
ee/tabby-webserver/src/integrations/github.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1951      +/-   ##
==========================================
+ Coverage   55.71%   55.84%   +0.13%     
==========================================
  Files         132      132              
  Lines       11587    11637      +50     
==========================================
+ Hits         6456     6499      +43     
- Misses       5131     5138       +7     

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[wsxiaoys]

autofix is still broken?