AprRequirement should not generate a build-time dependency

We want the apr requirement to act as a build-time requirement in case
it is satisfied (that is, the CLT is installed), as the resulting
binaries will link to the system libapr which is always present.

When it is *not* satisfied by the CLT, and we need to install the
formula, we have to treat it as a runtime dependency since the resulting
binaries will link to it.

Fixes Homebrew/homebrew#36301.
Fixes Homebrew/homebrew#36438.
Closes Homebrew/homebrew#36443.

Library/Homebrew/requirements/apr_dependency.rb

@@ -14,4 +14,12 @@ class AprDependency < Requirement
       ENV.prepend_path "PKG_CONFIG_PATH", "#{Formula["apr-util"].opt_libexec}/lib/pkgconfig"
     end
   end
+
+  def to_dependency
+    super.extend Module.new {
+      def tags
+        super - [:build]
+      end
+    }
+  end
 end