[Backport 4.5] changelog for 4.5.1 (#48157)

Backport 7b927ed from #48155.

Co-authored-by: coury-clark <[email protected]>

Author: github-actions[bot]

CHANGELOG.md

@@ -31,6 +31,13 @@ All notable changes to Sourcegraph are documented in this file.
 
 -
 
+## 4.5.1
+
+### Changed
+
+- Updated git to version 2.39.2 to address [reported security vulnerabilities](https://github.blog/2023-02-14-git-security-vulnerabilities-announced-3/) [#47892](https://github.com/sourcegraph/sourcegraph/pull/47892/files)
+- Updated curl to 7.88.1 to address [reported security vulnerabilities](https://curl.se/docs/CVE-2022-42915.html) [#48144](https://github.com/sourcegraph/sourcegraph/pull/48144)
+
 ## 4.5.0
 
 ### Added