fix(tests): Remove nitro canary test job (#20473)

There is no stable stream of Nitro 3 canary builds yet, so no point in
having this. I will add it back once we have a stable stream of builds,
likely after the full v3 release.

I probably had it at one point then didn't remove it properly before
merging #19224

Closes #20472

Author: logaretm

.github/workflows/canary.yml

@@ -120,9 +120,6 @@ jobs:
           - test-application: 'nestjs-microservices'
             build-command: 'test:build-latest'
             label: 'nestjs-microservices (latest)'
-          - test-application: 'nitro-3'
-            build-command: 'test:build-canary'
-            label: 'nitro-3 (canary)'
 
     steps:
       - name: Check out current commit