chore: change snapshot url in pom

[borisrizov-zf]

Description

Use legacy Sonatype staging url, as the credentials are not valid for the new one.

Pre-review checks

Please ensure to do as many of the following checks as possible, before asking for committer review:

• DEPENDENCIES are up-to-date. Dash license tool. Committers can open IP issues for restricted libs.
• Copyright and license header are present on all affected files