Update changelog and version after v2.20.3

CHANGELOG.md

@@ -1,5 +1,9 @@
 # CodeQL Action Changelog
 
+## [UNRELEASED]
+
+No user facing changes.
+
 ## 2.20.3 - 06 Jul 2023
 
 - Update default CodeQL bundle version to 2.13.5. [#1743](https://github.com/github/codeql-action/pull/1743)

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "codeql",
-  "version": "2.20.3",
+  "version": "2.20.4",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "codeql",
-      "version": "2.20.3",
+      "version": "2.20.4",
       "license": "MIT",
       "dependencies": {
         "@actions/artifact": "^1.1.0",

package.json

@@ -1,6 +1,6 @@
 {
   "name": "codeql",
-  "version": "2.20.3",
+  "version": "2.20.4",
   "private": true,
   "description": "CodeQL action",
   "scripts": {