Update CODEOWNERS with GitHub team identifiers after move

Author: sj

CODEOWNERS

@@ -1,8 +1,8 @@
-/cpp/ @Semmle/cpp-analysis
-/csharp/ @Semmle/cs
-/java/ @Semmle/java
-/javascript/ @Semmle/js
-/python/ @Semmle/python
+/cpp/ @github/codeql-c-analysis
+/csharp/ @github/codeql-csharp
+/java/ @github/codeql-java
+/javascript/ @github/codeql-javascript
+/python/ @github/codeql-python
 /cpp/**/*.qhelp @hubwriter
 /csharp/**/*.qhelp @jf205
 /java/**/*.qhelp @felicitymay