Update LittleFS Platformio example

[Jason2866]

Actual Platformio Platform espressif32 do not need anymore the Python script to build the LittleFS image.
Use custom partition scheme to guarantee to have a SPIFFS partition which works with the example code.

[github-actions]

Warnings

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Some issues found for the commit messages in this PR: the commit message "rm not anymore needed LittleFS Builder.py": summary looks empty type/action looks empty the commit message "use custom partition scheme": 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 Jason2866, we appreciate your contribution to this project!

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[3110]

I think board_build.filesystem = littlefs is necessary in platformio.ini.