[release] Group all hello world tests together (#57920)

It used to be in 3 different groups, now unionized in 1.

Signed-off-by: kevin <[email protected]>
Signed-off-by: Kamil Kaczmarek <[email protected]>

Author: khluu

release/release_tests.yaml

@@ -110,7 +110,7 @@
 
 - name: hello_world_custom_byod
   team: reef
-  group: hello_world_custom_byod
+  group: hello_world
   frequency: nightly
   working_dir: hello_world_tests
 
@@ -136,7 +136,7 @@
 
 - name: hello_world_custom_byod_depset_only
   team: reef
-  group: hello_world_custom_byod_depset
+  group: hello_world
   frequency: nightly
   working_dir: hello_world_tests