[php-src] Issue #20952: `opcache.file_cache_only = On` cause SEGV in `php_request_shutdown`

Issue: https://github.com/php/php-src/issues/20952
Author: cchangwen

### Description

`opcache.file_cache_only = On` cause SEGV in `php_request_shutdown`

The report appear and disappear when `opcache.file_cache_only` turn on and off.

```
AddressSanitizer:DEADLYSIGNAL
=================================================================
==159==ERROR: AddressSanitizer: SEGV on unknown address 0x007fbfff8041 (pc 0x56494e706f73 bp 0x7ffd15137390 sp 0x7ffd151372e0 T0)
==159==The signal is caused by a READ memory access.
    #0 0x56494e706f73  (/usr/local/bin/php+0x3da7f73) (BuildId: e5d03ae744c419767c29ba2eda688831cb4e619c)
    #1 0x56494e70b2f6 in _efree (/usr/local/bin/php+0x3dac2f6) (BuildId: e5d03ae744c419767c29ba2eda688831cb4e619c)
    #2 0x56494e4c3a20  (/usr/local/bin/php+0x3b64a20) (BuildId: e5d03ae744c419767c29ba2eda688831cb4e619c)
    #3 0x56494e4c333a in php_request_shutdown (/usr/local/bin/php+0x3b6433a) (BuildId: e5d03ae744c419767c29ba2eda688831cb4e619c)
    #4 0x56494f69b24c  (/usr/local/bin/php+0x4d3c24c) (BuildId: e5d03ae744c419767c29ba2eda688831cb4e619c)
    #5 0x56494f69638a  (/usr/local/bin/php+0x4d3738a) (BuildId: e5d03ae744c419767c29ba2eda688831cb4e619c)
    #6 0x7f892a169a2f  (/lib/ld-musl-x86_64.so.1+0x41a2f) (BuildId: 25262d1f0190fa67ac8949c47edb1488aae52fcd)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV (/usr/local/bin/php+0x3da7f73) (BuildId: e5d03ae744c419767c29ba2eda688831cb4e619c) 
==159==ABORTING
Aborted
```

### PHP Version

```plain
PHP 8.3.29 (cli) (built: Jan 13 2026 18:36:06) (NTS DEBUG)
Copyright (c) The PHP Group
Zend Engine v4.3.29, Copyright (c) Zend Technologies
    with Zend OPcache v8.3.29, Copyright (c), by Zend Technologies
```

### Operating System

Alpine Linux 3.23