replace '--chmod=+x' with '--chmod=755' for 'COPY' instructions in Dockerfile to be podman-friendly

[fullkomnun]

Description and Related Issue(s)

Usage of COPY instructions with '--chmod=+x' works with docker (if buildkit is enabled) but not with podman

Proposed Changes

Replace '--chmod=+x' with '--chmod=755' for 'COPY' instructions in Dockerfile to be podman-friendly while still supporting docker

Breaking or Incompatible Changes

Should not break build of container image with docker/podman

Additional Information

Could not test on Windows 10/11 with WSL2 to verify

Checklist for PR author

• I have tested these changes locally.
• I added tests to cover any new functionality, following this guide
• Whenever I fix a bug, I include a regression test to ensure that the bug does not reappear silently.
• If I have added, changed, renamed, or removed an environment variable
  • I updated the list of environment variables in the documentation
  • I made the necessary changes to the validator script according to the guide
  • I added "ENVs" label to this pull request