test(smoketest): use test-applications with agent 0.4.1-snapshot

[andrewazores]

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Related to #402
Depends on cryostatio/test-applications#9

Description of the change:

This change allows an environment variable to be configured so that...

Motivation for the change:

This change is helpful because users may want to...

How to manually test:

1. Run CRYOSTAT_IMAGE=quay.io... bash smoketest.bash...
2. ...

[github-actions]

This PR/issue depends on:

• ci(tags): lowercase image tags test-applications#9
  By Dependent Issues (🤖). Happy coding!