bugfix: rocksDB opens the same file multiple times

[funky-eyes]

• I have registered the PR changes.

Ⅰ. Describe what this PR did

Ⅱ. Does this pull request fix one issue?

fixes #6844

Ⅲ. Why don't you add test cases (unit test/integration test)?

Ⅳ. Describe how to verify it

Ⅴ. Special notes for reviews

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 2 lines in your changes missing coverage. Please review.

Project coverage is 52.37%. Comparing base (42f3ae7) to head (b6406a1).
Report is 1 commits behind head on 2.x.

Files with missing lines	Patch %	Lines
...g/apache/seata/server/instance/ServerInstance.java	0.00%	1 Missing ⚠️
...org/apache/seata/server/session/SessionHolder.java	0.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##                2.x    #6845      +/-   ##
============================================
+ Coverage     52.34%   52.37%   +0.03%     
- Complexity     6382     6383       +1     
============================================
  Files          1081     1081              
  Lines         37617    37615       -2     
  Branches       4464     4462       -2     
============================================
+ Hits          19690    19701      +11     
+ Misses        15974    15962      -12     
+ Partials       1953     1952       -1     

Files with missing lines	Coverage Δ
...g/apache/seata/server/instance/ServerInstance.java	9.37% <0.00%> (-3.13%)	⬇️
...org/apache/seata/server/session/SessionHolder.java	51.31% <0.00%> (+0.01%)	⬆️

... and 4 files with indirect coverage changes