Add version 2.5.3 to dwd-icon-tools.

spack_repo/packages/dwd-icon-tools/package.py

@@ -41,6 +41,7 @@ class DwdIconTools(Package):
         password = token
         url = "{}://{}:{}@{}/{}".format(parsed.scheme, user, password, parsed.netloc, parsed.path)
 
+    version("2.5.3", branch="icontools-2.5.3")
     version("2.5.2", branch="icontools-2.5.2")
 
     depends_on("netcdf-c")