[Feature-8530][API] add system default timezone if no user timezone when get userInfo

[caishunfeng]

issue: #8530

Purpose of the pull request

Brief change log

Verify this pull request

This pull request is code cleanup without any test coverage.

(or)

This pull request is already covered by existing tests, such as (please describe tests).

(or)

This change added tests and can be verified as follows:

[caishunfeng]

PTAL @devosend @songjianet

[codecov-commenter]

Codecov Report

Merging #8899 (c92f01c) into dev (db64dca) will decrease coverage by 5.52%.
The diff coverage is 27.30%.

❗ Current head c92f01c differs from pull request most recent head 18ba3c0. Consider uploading reports for the commit 18ba3c0 to get more accurate results

@@             Coverage Diff              @@
##                dev    #8899      +/-   ##
============================================
- Coverage     45.30%   39.77%   -5.53%     
- Complexity     4082     4262     +180     
============================================
  Files           702      808     +106     
  Lines         27177    32544    +5367     
  Branches       2907     3647     +740     
============================================
+ Hits          12312    12946     +634     
- Misses        13704    18372    +4668     
- Partials       1161     1226      +65     

Impacted Files	Coverage Δ
...cheduler/api/controller/AccessTokenController.java	88.23% <ø> (ø)
...uler/api/controller/ProcessInstanceController.java	72.09% <ø> (ø)
.../api/controller/ProcessTaskRelationController.java	21.42% <ø> (ø)
...hinscheduler/api/controller/ProjectController.java	68.00% <ø> (ø)
...nscheduler/api/controller/ResourcesController.java	57.89% <0.00%> (-1.04%)	⬇️
...duler/api/controller/TaskDefinitionController.java	3.22% <ø> (ø)
...nscheduler/api/controller/TaskGroupController.java	81.81% <ø> (ø)
...heduler/api/controller/TaskInstanceController.java	55.55% <ø> (ø)
...inscheduler/api/controller/UiPluginController.java	100.00% <ø> (ø)
...lphinscheduler/api/controller/UsersController.java	61.53% <ø> (ø)
... and 374 more

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[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

75.0% Coverage
0.0% Duplication

[devosend]

LGTM

[songjianet]

LGTM