fix: fix builds on darwin for PHP <= 7.3

Context: #201 (comment)
Related PR: #201

Author: drupol

pkgs/phps.nix

@@ -43,9 +43,7 @@ let
 
               "--enable-libxml"
               "--with-libxml-dir=${prev.libxml2.dev}"
-            ]
-            ++ prev.lib.optionals (prev.lib.versionAtLeast args.version "7.3") [
-              "--with-pcre-regex=${prev.pcre2.dev}"
+              "--with-pcre-regex=${prev.pcre2.dev}/include"
             ];
 
           buildInputs =