version: Update version and changelog after 7.4 release.

docs/overview/changelog.md

@@ -19,6 +19,23 @@ log][commit-log] for an up-to-date list of all changes.
 
 ## Zulip Server 7.x series
 
+### Zulip Server 7.4
+
+_Released 2023-09-15_
+
+- CVE-2023-4863: Upgrade vulnerable `libwebp` dependency.
+- Fixed a left sidebar layout bug affecting languages like Russian
+  with very long translations of certain menu items.
+- Fixed a bug in the reverse proxy misconfiguration warnings
+  introduced in 7.2.
+- Fixed a bug causing some exception report emails generated by the
+  Zulip server to be unpleasantly verbose.
+- Fixed the compose area “Enter sends” configuration incorrectly
+  advertising “Enter” instead of “Return” on macOS systems.
+- Fixed a CSS bug in the password reset form introduced in 7.3.
+- Improved troubleshooting guide discussion of restarting services.
+- Upgrade dependencies.
+
 ### Zulip Server 7.3
 
 _Released 2023-08-25_

version.py

@@ -14,7 +14,7 @@ ZULIP_VERSION = lines.pop(0).strip()
 ZULIP_MERGE_BASE = lines.pop(0).strip()
 
 LATEST_MAJOR_VERSION = "7.0"
-LATEST_RELEASE_VERSION = "7.3"
+LATEST_RELEASE_VERSION = "7.4"
 LATEST_RELEASE_ANNOUNCEMENT = "https://blog.zulip.com/2023/05/31/zulip-7-0-released/"
 
 # Versions of the desktop app below DESKTOP_MINIMUM_VERSION will be