internal/rosa: create /bin symlinks via helper

This centralises the workaround for surprisingly common buggy scripts with nonstandard hardcoded paths.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/rosa/package/git.az

@@ -12,8 +12,6 @@ package git {
 	};
 
 	early = `
-ln -s ../../system/bin/perl /usr/bin/ || true
-
 # test suite assumes apache
 rm -f /system/bin/httpd
 `;
@@ -22,6 +20,8 @@ rm -f /system/bin/httpd
 	enterSource = true;
 	env = [ "NO_RUST=YesPlease" ];
 
+	bin = [ "perl" ];
+	populateUsrBin = true;
 	exec = make {
 		inPlace = true;
 		generate = "make configure";