Fix --dry-run with --filename Tests for All Start Commands

[danielhelfand]

The tests for #911, #924, and #927 introduced some issues for --dry-run with --filename tests for all start commands:

• Dry run with output=json is duplicated for each sets of tests. For all commands, the test already exists and is now just running the exact same test again
• Renaming Dry Run using --filename tests to include the version number it is being tested against (i.e. v1beta1 versus v1alpha1) to avoid confusion that these are the same tests
• Switch the Dry Run with output=json -f v1beta1 Task start test to actually use a v1beta1 Task as opposed to a v1alpha1 Task

Submitter Checklist

• Includes tests (if functionality changed/added)
• Run the code checkers with make check
• Regenerate the manpages, docs and go formatting with make generated
• Commit messages follow commit message best practices

Release Notes

N/A

[pradeepitm12]

/lgtm

[piyush-garg]

/approve
/lgtm

[tekton-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: piyush-garg

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