Fixes #31228 - Improve UUID check performance

Doing a full match for regexp including saving match data is slow when
all we care about is whether it is a UUID or not. Instead first rule out
quick checks (not a string, wrong length) and only then check with
`.match?` instead of `=~` which just returns a boolean without saving
the match data.

lib/foreman.rb

@@ -2,14 +2,14 @@
 module Foreman
   # generate a UUID
   def self.uuid
-    SecureRandom.uuid.to_s
+    SecureRandom.uuid
   end
 
   UUID_REGEXP = Regexp.new("^([0-9a-f]{8})-([0-9a-f]{4})-([0-9a-f]{4})-" +
-                           "([0-9a-f]{2})([0-9a-f]{2})-([0-9a-f]{12})$")
+                           "([0-9a-f]{4})-([0-9a-f]{12})$")
   # does this look like a UUID?
   def self.is_uuid?(str)
-    !!(str =~ UUID_REGEXP)
+    str.is_a?(String) && str.length == 36 && str.match?(UUID_REGEXP)
   end
 
   def self.in_rake?(*rake_tasks)