Merged PR 30732: [release/v7.3.12] Update CHANGELOG

[release/v7.3.12] Update `CHANGELOG`

I've run `textlint --rule terminology <changedFileName-7.3.md>` and no error reported.

CHANGELOG/7.3.md

@@ -1,5 +1,31 @@
 # 7.3 Changelog
 
+## [7.3.12] - 2024-04-11
+
+### Build and Packaging Improvements
+
+<details>
+
+<summary>
+
+<p>Bump to .NET 7.0.18</p>
+
+</summary>
+
+<ul>
+<li>Update SDK, dependencies and <code>cgmanifest</code> for <code>7.3.12</code></li>
+<li>Revert changes to <code>packaging.psm1</code></li>
+<li>Verify environment variable for OneBranch before we try to copy (#21441)</li>
+<li>Multiple fixes in official build pipeline (#21408)</li>
+<li>PowerShell co-ordinated build OneBranch pipeline (#21364)</li>
+<li>Add <code>dotenv</code> install as latest version does not work with current Ruby version (#21239)</li>
+<li>Remove <code>surrogateFile</code> setting of <code>APIScan</code> (#21238)</li>
+</ul>
+
+</details>
+
+[7.3.12]: https://github.com/PowerShell/PowerShell/compare/v7.3.11...v7.3.12
+
 ## [7.3.11] - 2024-01-11
 
 ### Build and Packaging Improvements