[AssetMapper] Deprecate unused method splitPackageNameAndFilePath

[fabpot]

Q	A
Feature PR	symfony/symfony#54125
PR author(s)	@smnandre
Merged in	7.1

We created this issue to not forget to document this new feature. We would really appreciate if you can help us with this task. If you are not sure how to do it, please ask us and we will help you.

To fix this issue, please create a PR against the 7.1 branch in the symfony-docs repository.

Thank you! 😃

[smnandre]

I'm not sure this will require any doc, as the method was never used if i'm not mistaken :)

[javiereguiluz]

You are right Simon. Closing as "fixed" because this method wasn't mentioned in the docs. Thanks.