fix(ruby): accept both "_" and "." tag separators from ruby/ruby

ruby/ruby switched its release tag separator from "_" (e.g. v3_4_9)
to "." (e.g. v4.0.4) starting at Ruby 4.0.0. The current regex in
find_version_from_git_tags only matches the "_" form, so VERSION=latest
and ADDITIONAL_VERSIONS resolution silently skip every 4.x release.

When the caller passes "_" as the separator, build the regex with a
[._] character class so both tag styles are picked up. The existing
`tr "_" "."` normalization already produces correct dot-separated
output for both forms, so downstream sort/grep logic is unchanged.

Author: rhiroe

src/ruby/install.sh

@@ -150,13 +150,20 @@ find_version_from_git_tags() {
     local last_part_optional=${5:-"false"}    
     if [ "$(echo "${requested_version}" | grep -o "." | wc -l)" != "2" ]; then
         local escaped_separator=${separator//./\\.}
+        # ruby/ruby switched its tag separator from "_" (e.g. v3_4_5) to "." (e.g. v4.0.0)
+        # starting at Ruby 4.0.0. When the caller asks for "_", accept either separator
+        # so both tag styles are picked up; `tr "_" "."` below normalizes the result.
+        local separator_regex="${escaped_separator}"
+        if [ "${separator}" = "_" ]; then
+            separator_regex="[._]"
+        fi
         local last_part
         if [ "${last_part_optional}" = "true" ]; then
-            last_part="(${escaped_separator}[0-9]+)?"
+            last_part="(${separator_regex}[0-9]+)?"
         else
-            last_part="${escaped_separator}[0-9]+"
+            last_part="${separator_regex}[0-9]+"
         fi
-        local regex="${prefix}\\K[0-9]+${escaped_separator}[0-9]+${last_part}$"
+        local regex="${prefix}\\K[0-9]+${separator_regex}[0-9]+${last_part}$"
         local version_list="$(git ls-remote --tags ${repository} | grep -oP "${regex}" | tr -d ' ' | tr "${separator}" "." | sort -rV)"
         if [ "${requested_version}" = "latest" ] || [ "${requested_version}" = "current" ] || [ "${requested_version}" = "lts" ]; then
             declare -g ${variable_name}="$(echo "${version_list}" | head -n 1)"