fix: disable Zend Signals and enable Zend Max Execution Timers for ZTS builds

[dunglas]

• Zend Signals are known to be currently broken with ZTS builds, they should be disabled
• The new Zend Max Execution Timers feature (specially designed for ZTS) fixes timeout support when using ZTS. It is enabled by default for ZTS build starting with PHP 8.3, but must be enabled manually for 8.1+ to preserve ABI compatibility, which isn't an issue here because we're creating a static build.

Related PHP issues:

• segmentation fault when sending SIGINT to PHP embedded in another program php/php-src#9649 (comment)
• Remove Zend signal handling php/php-src#5591 (comment)
• fix: support for timeouts with ZTS on Linux php/php-src#10141

The official ZTS Docker images also include these flags.

[crazywhalecc]

I don't know much about ZTS bugs, but based on the information you provided, we need to disable the zend signal, and there is no better solution.

And --enable-zend-max-execution-timers makes ZTS safer.

Am I right?

[dunglas]

Exactly.