Fix for failed pipeline `test-doc` (#2127)

Fix for failed pipeline `test-doc`:
https://gitlab.parity.io/parity/mirrors/polkadot-sdk/-/jobs/4174859
I just wonder how could have other PR been merged after this was merged:
https://github.com/paritytech/polkadot-sdk/pull/1714/files#diff-1bde7bb2be0165cbe6db391e10a4a0b2f333348681373a86a0f8502d14d20d32R56