Bump version to v6.0-RC2 (Project-OSRM#7148)

Author: DennisOSRM

CHANGELOG.md

@@ -1,9 +1,13 @@
 # Unreleased
+  - Changes from 6.0.0 RC2
+
+# 6.0.0 RC2
   - Changes from 6.0.0 RC1
-    - Features
-      - REMOVED: Remove deprecated contractor config settings [#7149](https://github.com/Project-OSRM/osrm-backend/pull/7149)
     - Build:
       - CHANGED: Updated Conan to v2.15.0 [#7148](https://github.com/Project-OSRM/osrm-backend/pull/7148)
+      - CHANGED: Back to installing header files and lib [#7140](https://github.com/Project-OSRM/osrm-backend/pull/7140)
+    - Misc:
+      - CHANGED: Updated documentation library [#6677](https://github.com/Project-OSRM/osrm-backend/pull/6677)
 
 # 6.0.0 RC1
   - Changes from 5.27.1