feat(entrypoint.sh): support four digit version numbers

entrypoint.sh

@@ -11,7 +11,7 @@ VERSION_NAME="${INPUT_VERSION_NAME:-REVIEWDOG_VERSION}"
 
 # Get current version.
 # NOTE: Go to https://regex101.com/r/t1JcmL/13 To see the current regex in action.
-CURRENT_VERSION=$(grep -oP "${VERSION_NAME}(?:\s*=\s*|:?\s*)[\"|\']?v?\K\d+\.\d+(\.\d+)?(-[^\'\"\s]*)?" "${FILE}" | head -n1)
+CURRENT_VERSION=$(grep -oP "${VERSION_NAME}(?:\s*=\s*|:?\s*)[\"|\']?v?\K\d+\.\d+(\.\d+)(\.\d+)?(-[^\'\"\s]*)?" "${FILE}" | head -n1)
 if [ -z "${CURRENT_VERSION}" ]; then
   echo "cannot parse ${VERSION_NAME}"
   exit 1