Do not add new compaction mod file in deletion

[jt2594838]

The old mechanism uses a "compaction mod file" to record deletions during compaction and merge them into the modification file of the compacted file.
However, this encounters concurrent issues during the process of "merging deletions into the modification file of the compacted file".
Therefore, it is replaced with the new mechanism using cascading modification files to write deletions during compaction also to the compacted files' modification file.

For compatibility with systems that have already generated compaction mods, the old mechanism is kept to handle the recovery and deletion of the compaction mods.
But no new compaction mods should be created, which is to be fixed in this PR.

This also avoids meeting null compaction mods during deletion because after exiting the synchronized block below, the compaction mods may just be set to null by compaction.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 39.40%. Comparing base (e4e3c29) to head (8778a4a).
Report is 19 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #15281      +/-   ##
============================================
+ Coverage     39.37%   39.40%   +0.02%     
  Complexity      193      193              
============================================
  Files          4637     4638       +1     
  Lines        298744   298981     +237     
  Branches      37276    37321      +45     
============================================
+ Hits         117638   117799     +161     
- Misses       181106   181182      +76     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.