Accept some latest:<regex> versions

According to the tfenv documentation https://github.com/tfutils/tfenv#terraform-version-file, versions can also be specified using a regex, where the most common one, a prefix match, is now also supported by this plugin

Author: skruppy

bin/parse-legacy-file

@@ -53,7 +53,7 @@ get_legacy_version() {
   [[ ${this_plugin_supported} == false ]] && return 0
 
   if [[ ${version_file} == *".${THIS_PLUGIN}-version" && -r ${version_file} ]]; then
-    cat "${version_file}"
+    cat "${version_file}" | sed -e 's/^latest:\^//g'
   elif [[ ${version_file} =~ ${ASDF_HASHICORP_TERRAFORM_VERSION_FILE:-main.tf} && -r ${version_file} ]]; then
     read_version_from_main_tf "${version_file}"
   fi