Fix postgres script permissions

[hajnalmt]

The initdb.sh and the upgrade.sh scripts in the postgres image were not owned by the postgres user, which made them failing with permission denied errors in some local builds.

Comprehensive Summary of your change

Adding the scripts to the appropriate user and fixing the permissions resolved the issue.

Issue being fixed

Fixes #21006

Please indicate you've done the following:

• Well Written Title and Summary of the PR
• Label the PR as needed. "release-note/ignore-for-release, release-note/new-feature, release-note/update, release-note/enhancement, release-note/community, release-note/breaking-change, release-note/docs, release-note/infra, release-note/deprecation"
• Accepted the DCO. Commits without the DCO will delay acceptance.
• Made sure tests are passing and test coverage is added if needed.
• Considered the docs impact and opened a new docs issue or PR with docs changes if needed in website repository.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 66.16%. Comparing base (c8c11b4) to head (b1a3cb2).
Report is 299 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##             main   #21007       +/-   ##
===========================================
+ Coverage   45.36%   66.16%   +20.79%     
===========================================
  Files         244     1048      +804     
  Lines       13333   114471   +101138     
  Branches     2719     2856      +137     
===========================================
+ Hits         6049    75740    +69691     
- Misses       6983    34587    +27604     
- Partials      301     4144     +3843     

Flag	Coverage Δ
unittests	66.16% <ø> (+20.79%)	⬆️

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