Add web/src/main/webapp/WEB-INF/data/data/resources/schemapublication folder to .gitignore

[josegar74]

This changes adds the folder web/src/main/webapp/WEB-INF/data/data/resources/schemapublication to .gitignore, as should not be committed in the code repository.

Related to #7337

Checklist

• I have read the [contribution guidelines](https://github.com/geonetwork/core-geonetwork/blob/main/CONTRIBUTING.md
• Pull request provided for main branch, backports managed with label
• Good housekeeping of code, cleaning up comments, tests, and documentation
• Clean commit history broken into understandable chucks, avoiding big commits with hundreds of files, cautious of reformatting and whitespace changes
• Clean commit messages, longer verbose messages are encouraged
• API Changes are identified in commit messages
• Testing provided for features or enhancements using automatic tests)
• User documentation provided for new features or enhancements in mannual
• Build documentation provided for development instructions in README.md files
• Library management using pom.xml dependency management. Update build documentation with intended library use and library tutorials or documentation

[jodygarnett]

Ignoring generated content is fine.

I prefer to generate into target folder and stage war content there.