fix: use default user from env

[td-famedly]

this just changes the default, but if you had previously overwritten it in your repo you still have to change that

[github-actions]

* 708001c53ab14c4944f270f5b1f5c0271a215a29 fix: use default user from env
|   - Error: Bad signature: Malformed MPI: leading bit is not set: expected bit 8 to be set in   101110 (2e)
* 57b383862ba81dfa265bb33d492e2bbcbc96891d Revert "chore(docker): use clean_registry in step `Create manifest list and push`"
    - Trust root.

Failed to authenticate commits.

Error: Could not verify commits 57b383862ba81dfa265bb33d492e2bbcbc96891d..708001c53ab14c4944f270f5b1f5c0271a215a29

Caused by:
    0: While verifying commit 708001c53ab14c4944f270f5b1f5c0271a215a29
    1: Bad signature: Malformed MPI: leading bit is not set: expected bit 8 to be set in   101110 (2e)