Remove ext/random backwards-compatibility headers

When ext/random was initially added in PHP 8.2, these headers started
“forwarding” to the new ext/random/php_random.h to reduce the impact on
existing extensions.

As master already contains some breaking changes of the internal API of
ext/random and as the last PHP version without ext/random will be EOL once
master is released, it appears appropriate to drop these headers now.

Author: TimWolla

UPGRADING.INTERNALS

@@ -26,6 +26,10 @@ PHP 8.4 INTERNALS UPGRADE NOTES
   Z_PARAM_FUNC_EX2 was added as well with the same arguments as Z_PARAM_FUNC_EX
   plus an additional argument free_trampoline.
 
+* The backwards compatibility headers ext/standard/{php_lcg.h,php_mt_rand.h,
+  php_rand.h,php_random.h} have been removed. Include ext/random/php_random.h
+  directly.
+
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