chore: remove all mbstring.func_overload references

[joshtrichards]

Summary

• Deprecated in PHP 7.2
• Completely removed in PHP 8.0
• https://www.php.net/manual/en/mbstring.configuration.php#ini.mbstring.func-overload

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)

[solracsf]

Conflicts :/

[come-nc]

Rebased and solved conflicts

[skjnldsv]

Related

There was 1 error:

1) Test\IntegrityCheck\CheckerTest::testWriteCoreSignatureWithValidModifiedHtaccess
Exception: /home/runner/actions-runner/_work/server/server/tests/data/integritycheck/htaccessWithValidModifiedContent/core is not writable

/home/runner/actions-runner/_work/server/server/lib/private/IntegrityCheck/Checker.php:242
/home/runner/actions-runner/_work/server/server/tests/lib/IntegrityCheck/CheckerTest.php:617

--

There was 1 failure:

1) Test\IntegrityCheck\CheckerTest::testVerifyCoreSignatureWithValidModifiedHtaccessSignatureData
Failed asserting that two arrays are identical.
--- Expected
+++ Actual
@@ @@
-Array &0 []
+Array &0 [
+    'INVALID_HASH' => Array &1 [
+        '.htaccess' => Array &2 [
+            'expected' => '7e6a7a4d8ee4f3fbc45dd579407c643471575a9d127d1c75f6d0a49e80766c3c587104b2139ef76d2a4bffce3f45777900605aaa49519c9532909b71e5030[227](https://github.com/nextcloud/server/actions/runs/17121732682/job/48564026759?pr=53578#step:7:228)',
+            'current' => 'b1a6a9fbb85417f3f461e654f1a8ae56a131fe54e4257b2b8b7ba6b3fedd55b83c0df20550cd6c52bd3a96d148a5a3c4ea24d99dca5d45a644491e56ad99df8e',
+        ],
+    ],
+]

[come-nc]

I do not know what’s the correct way to update those hashes.
I’m surprised only one test fails, there are others that seem to depend on hardcoded hashes for .htaccess.

@nickvergessen You’re the last one to touch those hashes (6 years ago 🙈 ), do you know what’s to do?

[nickvergessen]

Just to have it "documented"

You’re the last one to touch those hashes (6 years ago 🙈 ), do you know what’s to do?

Dummy thought is:

server/tests/lib/IntegrityCheck/CheckerTest.php

Lines 734 to 738 in b7c1594

	// When updating the mimetype list the test assets need to be updated as well
	// 1. Update core/js/mimetypelist.js with the new generated js by running the test with the next line uncommented:
	// file_put_contents(\OC::$SERVERROOT . '/tests/data/integritycheck/mimetypeListModified/core/js/mimetypelist.js', $newFile);
	// 2. Update signature.json using the following occ command:
	// occ integrity:sign-core --privateKey=./tests/data/integritycheck/core.key --certificate=./tests/data/integritycheck/core.crt --path=./tests/data/integritycheck/mimetypeListModified

But what I did was:
INSIDE of:

server/tests/lib/IntegrityCheck/CheckerTest.php

Lines 603 to 605 in b7c1594

	$this->callback(function ($signature) use ($expectedSignatureFileData) {
	$expectedArray = json_decode($expectedSignatureFileData, true);
	$actualArray = json_decode($signature, true);

Print actual values. Update the hash (L588) and signature (L591) in this test and use the same values in testVerifyCoreSignatureWithValidModifiedHtaccessSignatureData