Really update machine to current everywhere (#74)

The change in 6.0.0. updated the default executor to use the current
ubuntu machine image by default, but didn't update the job's machine
parameter's default value also (which is passed in to the default
executor and overrides the default value that was changed!)

This commit updates the default value of the machine parameter in the
job too, ensuring everywhere that a default is used anyhow we always
end up with the current ubuntu image rather than a deprecated one.

src/jobs/deploy.yml

@@ -5,7 +5,7 @@ executor:
   machine_image: <<parameters.machine_image>>
 parameters:
   machine_image:
-    default: ubuntu-2204:2022.07.1
+    default: ubuntu-2204:current
     type: string
     description: >
       The CircleCI Linux Machine VM Image for this job. Find other available machine images here: https://circleci.com/docs/2.0/configuration-reference/#available-machine_images