message: Update CHANGELOG.md
  Add message about `rb/weak-cryptographic-algorithm`.
diff: ## 2.1.31 - 04 Nov 2022
  -No user facing changes.
  +- The `rb/weak-cryptographic-algorithm` Ruby query has been updated to no longer report uses of hash functions such as `MD5` and `SHA1` even if they are known to be weak. These hash algorithms are used very often in non-sensitive contexts, making the query too imprecise in practice. [#1344](https://github.com/github/codeql-action/pull/1344)
  ## 2.1.30 - 02 Nov 2022
  