Fix GH-17246: GC during SCCP causes segfault

This bug happens because of a nested `SHM_UNPROTECT()` sequence.
In particular:
```
unprotect memory at ext/opcache/ZendAccelerator.c

Fix GH-17246: GC during SCCP causes segfault

This bug happens because of a nested `SHM_UNPROTECT()` sequence.
In particular:
```
unprotect memory at ext/opcache/ZendAccelerator.c:2127
protect memory at ext/opcache/ZendAccelerator.c:2160
unprotect memory at ext/opcache/ZendAccelerator.c:2164
unprotect memory at ext/opcache/jit/zend_jit_trace.c:7464
^^^ Nested
protect memory at ext/opcache/jit/zend_jit_trace.c:7591
^^^ Problem is here: it should not protect again due to the nested unprotect
protect memory at ext/opcache/ZendAccelerator.c:2191
^^^ This one should actually protect, not the previous one
```

The reason this nesting happen is because:
1. We try to include the script, this eventually calls `cache_script_in_shared_memory`
2. `zend_optimize_script` will eventually run SCCP as part of the DFA pass.
3. SCCP will try to replace constants, but can also run destructors when a partial array is destructed here:

https://github.com/php/php-src/blob/4e9cde758eadf30cc4d596d6398c2c34c64197b4/Zend/Optimizer/sccp.c#L2387-L2389

In this case, this destruction invokes the GC which invokes the tracing JIT,
leading to the nested unprotects.

This patch disables the GC to prevent invoking user code, as user code
is not supposed to run during the optimizer pipeline.

Closes GH-17249.

Co-authored-by: Dmitry Stogov <dmitry@zend.com>

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