[BUGFIX] Reliably catch E_WARNING when unserialize() fails

[marvinschroeder]

Description

This PR should reliably catch the E_WARNING by unserialize().
As mentioned in the official RFC of the unserialize() change in PHP 8.3, this should be the preferred way of catching this error.

Should resolve #1087.

Sorry to not have checked all the points below, since all mentioned steps in the CONTRIBUTING.md not worked on my local machine.

Tested this code on a project with Typo3 v11.5.41 and PHP 8.3.13.

I have

• Checked that CGL are followed
• Checked that the Tests are still working
• Added description to CHANGELOG.md (github-handle is optional)
• Added tests for the new code

[tomasnorre]

Thanks for you PR. Could you have a look @cweiske? Would appreciate that.

[cweiske]

I've found out why my previous patch works for me: #1087 (comment)

The conclusion is that if $GLOBALS['TYPO3_CONF_VARS']['SYS']['exceptionalErrors'] includes E_WARNING, then this patch here is not necessary.

Since this is an easy workaround/solution, I'd not merge this patch here.

[tomasnorre]

Thanks for looking into it @cweiske. I'll close this issue.