Add fsync() support to SPIFFS VFS driver

[RathiSonika]

Added support for fsync() call in the SPIFFS VFS driver.

[CLAassistant]

All committers have signed the CLA.

[github-actions]

Warnings

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Some issues found for the commit messages in this PR: the commit message "Add fsync() support to SPIFFS VFS driver": summary looks empty type/action looks empty Please fix these commit messages - here are some basic tips: follow Conventional Commits style correct format of commit message should be: <type/action>(<scope/component>): <summary>, for example fix(esp32): Fixed startup timeout issue allowed types are: change,ci,docs,feat,fix,refactor,remove,revert,test sufficiently descriptive message summary should be between 20 to 72 characters and start with upper case letter avoid Jira references in commit messages (unavailable/irrelevant for our customers) TIP: Install pre-commit hooks and run this check when committing (uses the Conventional Precommit Linter).

👋 Hello RathiSonika, we appreciate your contribution to this project!

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[Alvin1Zhang]

Thanks for your contribution.

[RathiSonika]

Original PR #12693
Closing this PR. Thanks!