fix: reduce threshold for background job in PCV

[GursheenK]

Problem
The function to evaluate if the processing of GL entries in PCV should be done in a background job does not consider the number of closing entries.

Solution
Added closing entries in the condition for evaluating if the process will take place in the background job.
Reduced the threshold to ensure if entries are more than 3000, the process should use a background job.

[codecov]

Codecov Report

Merging #36900 (b6e6f2e) into develop (cd74c6c) will decrease coverage by 0.01%.
Report is 4 commits behind head on develop.
The diff coverage is 100.00%.

@@             Coverage Diff             @@
##           develop   #36900      +/-   ##
===========================================
- Coverage    65.42%   65.42%   -0.01%     
===========================================
  Files          794      794              
  Lines        62194    62194              
===========================================
- Hits         40690    40689       -1     
- Misses       21504    21505       +1     

Files Changed	Coverage
...e/period_closing_voucher/period_closing_voucher.py	100.00%