Updates for tfc-agent release 1.17.4 (#127)

Author: natalie-todd

website/docs/cloud-docs/agents/changelog.mdx

@@ -18,6 +18,11 @@ within each release are categorized into one or more of the following labels:
 Each version below corresponds to a release artifact available for download on
 the official [releases website](https://releases.hashicorp.com/tfc-agent/).
 
+## 1.17.4 (12/12/2024)
+
+BUG FIXES:
+* Surfaced errors due to invalid Sentinel output on errored Sentinel commands (#850)
+
 ## 1.17.3 (12/10/2024)
 
 BUG FIXES: