Update changelog and version after v2.1.15

CHANGELOG.md

@@ -1,5 +1,9 @@
 # CodeQL Action Changelog
 
+## [UNRELEASED]
+
+No user facing changes.
+
 ## 2.1.15 - 28 Jun 2022
 
 - CodeQL query packs listed in the `packs` configuration field will be skipped if their target language is not being analyzed in the current Actions job. Previously, this would throw an error. [#1116](https://github.com/github/codeql-action/pull/1116)

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "codeql",
-  "version": "2.1.15",
+  "version": "2.1.16",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "codeql",
-      "version": "2.1.15",
+      "version": "2.1.16",
       "license": "MIT",
       "dependencies": {
         "@actions/artifact": "^1.0.0",

package.json

@@ -1,6 +1,6 @@
 {
   "name": "codeql",
-  "version": "2.1.15",
+  "version": "2.1.16",
   "private": true,
   "description": "CodeQL action",
   "scripts": {