chore: add changelog for 13.8.0 release (#5810)

* chore: add changelog for 13.8.0 release

* Update docs/guides/references/changelog.mdx

Co-authored-by: Matt Schile <mschile@cypress.io>

* Update docs/guides/references/changelog.mdx

Co-authored-by: Matt Schile <mschile@cypress.io>

* Update docs/guides/references/changelog.mdx

---------

Co-authored-by: Matt Schile <mschile@cypress.io>

Author: AtofStryker

docs/guides/references/changelog.mdx

@@ -2,6 +2,22 @@
 title: Changelog
 ---
 
+## 13.8.0
+
+_Released 4/18/2024_
+
+**Features:**
+
+- Added support for `webpack-dev-server` `v5` to `@cypress/webpack-dev-server`. Addresses [#29305](https://github.com/cypress-io/cypress/issues/29305).
+
+**Bugfixes:**
+
+- Fixed a regression introduced in [`13.7.3`](https://docs.cypress.io/guides/references/changelog#13-7-3) where Cypress could hang handling long assertion messages. Fixes [#29350](https://github.com/cypress-io/cypress/issues/29350).
+
+**Misc:**
+
+- The [`SEMAPHORE_GIT_PR_NUMBER`](https://docs.semaphoreci.com/ci-cd-environment/environment-variables/#semaphore_git_pr_number) environment variable from [Semaphore](https://semaphoreci.com/) CI is now captured to display the linked PR number in the Cloud. Addressed in [#29314](https://github.com/cypress-io/cypress/pull/29314).
+
 ## 13.7.3
 
 _Released 4/11/2024_