random: Add missing php.h include to php_random.h (#10764)

`PHPAPI` is defined in `php.h`. It appears that without the explicit include,
recent versions of Visual Studio Code’s intellisense (rightfully) no longer
detect `PHPAPI`. This will then lead to a misparsing of the file, because
`PHPAPI` is assumed to be the return type and the actual return type is assumed
to be the function name, thus expecting a semicolon after the actual return
type. This in turn colors the entire header in red due to the detected syntax
error(s), making development very hard / impossible.

This did not cause issues outside of the IDE use case, because apparently all
users of `php_random.h` include `php.h` before including `php_random.h`.

Author: TimWolla

ext/random/php_random.h

@@ -31,6 +31,8 @@
 #ifndef PHP_RANDOM_H
 # define PHP_RANDOM_H
 
+# include "php.h"
+
 PHPAPI double php_combined_lcg(void);
 
 /*