Add support for Unreal 6 (#123)

List of issues we had:
 
* echo wallops missing `!user@host` [wallops: Send a full NUH as prefix in echoed WALLOPS unrealircd/unrealircd#186](https://github.com/unrealircd/unrealircd/pull/186)
* RPL_MONONLINE is (re)sent on nick case change - https://bugs.unrealircd.org/view.php?id=6013
* MONITOR accepts masks - https://bugs.unrealircd.org/view.php?id=6014
* KICK doesn't support multiple channels anymore, despite unchanged TARGMAX - https://bugs.unrealircd.org/view.php?id=6015

workflows.yml

@@ -246,12 +246,12 @@ software:
             make install
 
     unrealircd:
-        name: UnrealIRCd
+        name: UnrealIRCd 6
         repository: unrealircd/unrealircd
-        refs: &unrealircd_refs
-            stable: 94993a03ca8d3c193c0295c33af39270c3f9d27d  # 5.2.1-rc1
-            release: null
-            devel: unreal52
+        refs:
+            stable: d77f42e4bef388ae344256eeef9a8000345ae381  # 6.0.0 + 2 commits
+            release: 893bf864f6c616e891d84916d27e342c252f31aaa  # 6.0.0
+            devel: unreal60_dev
             devel_release: null
         path: unrealircd
         prefix: ~/.local/unrealircd
@@ -267,6 +267,19 @@ software:
             make -j 4
             make install
 
+    unrealircd-5:
+        name: UnrealIRCd 5
+        repository: unrealircd/unrealircd
+        refs:
+            stable: 94993a03ca8d3c193c0295c33af39270c3f9d27d  # 5.2.1-rc1
+            release: null
+            devel: unreal52
+            devel_release:
+        path: unrealircd
+        prefix: ~/.local/unrealircd
+        separate_build_job: true
+        build_script: *unrealircd_build_script
+
     #############################
     # Clients:
 
@@ -354,6 +367,9 @@ tests:
     ircu2:
         software: [ircu2]
 
+    unrealircd-5:
+        software: [unrealircd-5]
+
     unrealircd:
         software: [unrealircd]