[ec2 launcher] update ubuntu image suggestion (#46201)

use 22.04 rather than 18.04

Signed-off-by: Lonnie Liu <[email protected]>

python/ray/tests/project_files/session-tests/git-repo-pass/ray-project/project.yaml

@@ -10,7 +10,7 @@ cluster:
 
 environment:
   # dockerfile: The dockerfile to be built and ran the commands with.
-  # dockerimage: The docker image to be used to run the project in, e.g. ubuntu:18.04.
+  # dockerimage: The docker image to be used to run the project in, e.g. ubuntu:22.04.
   requirements: ray-project/requirements.txt
 
   shell: # Shell commands to be ran for environment setup.

python/ray/tests/project_files/session-tests/invalid-config-fail/ray-project/project.yaml

@@ -12,7 +12,7 @@ environment:
   # NOTE: The following is invalid because you can't have both dockerfile
   #       and dockerimage
   dockerfile: The dockerfile to be built and ran the commands with.
-  dockerimage: The docker image to be used to run the project in, e.g. ubuntu:18.04.
+  dockerimage: The docker image to be used to run the project in, e.g. ubuntu:22.04.
 
   requirements: ray-project/requirements.txt
 

python/ray/tests/project_files/session-tests/project-pass/ray-project/project.yaml

@@ -10,7 +10,7 @@ cluster:
 
 environment:
   # dockerfile: The dockerfile to be built and ran the commands with.
-  # dockerimage: The docker image to be used to run the project in, e.g. ubuntu:18.04.
+  # dockerimage: The docker image to be used to run the project in, e.g. ubuntu:22.04.
   requirements: ray-project/requirements.txt
 
   shell: # Shell commands to be ran for environment setup.