Add info about --disable-apache2-conf

[skip ci]

Author: petk

UPGRADING.INTERNALS

@@ -135,6 +135,8 @@ PHP 8.6 INTERNALS UPGRADE NOTES
     . --with-pic is now --enable-pic. The old flag will result in an error.
   . Symbol HAVE_ST_BLOCKS has been removed from php_config.h (use
     HAVE_STRUCT_STAT_ST_BLOCKS).
+  . Added a new configure option --disable-apache2-conf to prevent apxs from
+    editing httpd.conf during installation.
 
 - Windows build system changes:
   . Function SETUP_OPENSSL() doesn't accept 6th argument anymore and doesn't