argtable3: add livecheck

Upstream uses a tag format including a version and hash (e.g.,
`v3.2.2.f25c624`) and we only use the version part in the formula, so
this adds a `livecheck` block with a regex that omits the hash part
to match the formula version format. This makes it so that livecheck
won't incorrectly surface the tag with the hash as newer than the
same version without the hash.

Author: samford

Formula/a/argtable3.rb

@@ -7,6 +7,14 @@ class Argtable3 < Formula
   license "BSD-3-Clause"
   head "https://github.com/argtable/argtable3.git", branch: "master"
 
+  # Upstream uses a tag format including a version and hash (e.g.
+  # `v3.2.2.f25c624`) and we only use the version part in the formula, so this
+  # omits the hash part to match.
+  livecheck do
+    url :stable
+    regex(/^v?(\d+(?:\.\d+)+)(?:\.\h+)?$/i)
+  end
+
   bottle do
     sha256 cellar: :any,                 arm64_sequoia: "977cc6d2b39d50551e00be1cb664891ba886e3e63779769713815ab5c830d4f7"
     sha256 cellar: :any,                 arm64_sonoma:  "59140a12791b4cd3733fd383bbd91373d517ed6a22dded4ae9e74b8fd2039844"