fix(generator): align template and post-processor formatting

[blakeli0]

This PR aligns the owlbot.py.j2 template with the formatting expected by update_owlbot_postprocessor_config.sh (no trailing comma on the last element and ]) closing tag), and synchronizes the existing owlbot.py files.

[gemini-code-assist]

Code Review

This pull request modifies the formatting of owlbot.py and its Jinja2 template, specifically adjusting list item commas and closing brackets. A high-severity syntax error was identified in the template logic that would result in invalid Python code when template_excludes is provided, as it generates redundant closing parentheses. A fix was suggested to correctly handle the conditional closing of the function call.

[sonarqubecloud]

Quality Gate passed for 'gapic-generator-java-root'

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[sonarqubecloud]

Quality Gate passed for 'gapic-generator-java-root'

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[blakeli0]

cc: @zhumin8. We may need sync Librarian with this change.