fix(DoS): specify timeout in Regex ctor

This isn't actually a "fix", the method may be slow by design if the source is lazily enumerated. SonarCloud, however, did not like this method not having an explicit timeout. If SonarCloud continues to complain, we'll just shut its mouth masking tape and throw it in the broom closet.

X10D/src/Text/EnumerableExtensions.cs

@@ -72,7 +72,8 @@ public static IEnumerable<string> Grep(this IEnumerable<string> source, string p
         }
 #endif
 
-        var regex = new Regex(pattern, RegexOptions.Compiled | (ignoreCase ? RegexOptions.IgnoreCase : RegexOptions.None));
+        var options = RegexOptions.Compiled | (ignoreCase ? RegexOptions.IgnoreCase : RegexOptions.None);
+        var regex = new Regex(pattern, options, Regex.InfiniteMatchTimeout);
 
         foreach (string item in source)
         {