Gnome: Update default regex and version filtering

The `Gnome` strategy's default regex uses the `+` form of the standard
regex for matching versions like 1.2.3. However, with the switch to
the new version scheme, some packages had a release that omits a
minor and patch (i.e., `40` instead of `40.0`). The default regex
fails to match versions like this but the looser `*` form will match
both. [When creating regexes, we generally start with the `+` form
and only switch to the looser `*` form when it's necessary and
contextually-appropriate.]

This also updates the default version filtering logic that's applied
to versions using the old GNOME version scheme (below version 40).
Outside of the refactoring changes, this also filters out versions
where the patch number is 90+, as these are also unstable.

Library/Homebrew/livecheck/strategy/gnome.rb

@@ -66,7 +66,7 @@ module Homebrew
           # GNOME archive files seem to use a standard filename format, so we
           # count on the delimiter between the package name and numeric
           # version being a hyphen and the file being a tarball.
-          values[:regex] = /#{regex_name}-(\d+(?:\.\d+)+)\.t/i
+          values[:regex] = /#{regex_name}-(\d+(?:\.\d+)*)\.t/i
 
           values
         end
@@ -99,7 +99,11 @@ module Homebrew
             # Filter out unstable versions using the old version scheme where
             # the major version is below 40.
             version_data[:matches].reject! do |_, version|
-              version.major < 40 && (version.minor >= 90 || version.minor.to_i.odd?)
+              next if version.major >= 40
+              next if version.minor.blank?
+
+              (version.minor.to_i.odd? || version.minor >= 90) ||
+                (version.patch.present? && version.patch >= 90)
             end
           end
 

Library/Homebrew/test/livecheck/strategy/gnome_spec.rb

@@ -12,7 +12,7 @@ describe Homebrew::Livecheck::Strategy::Gnome do
   let(:generated) {
     {
       url:   "https://download.gnome.org/sources/abc/cache.json",
-      regex: /abc-(\d+(?:\.\d+)+)\.t/i,
+      regex: /abc-(\d+(?:\.\d+)*)\.t/i,
     }
   }