Update trigger pluginify versions

[itowlson]

So we don't need to keep updating the versions.

(The repo has a slightly funky layout but I think this will still work with the way it does the pluginifying. If not, well, back to the old way.)

[itowlson]

Also amended the canary workflow to hopefully NOT keep failing because "oh canary doesn't exist I can't delete it."

Sheesh.

[kate-goldenring]

@itowlson I think i am missing context. Did the release from this PR fail so this is "bumping" a retry? https://github.com/spinframework/spin-trigger-plugins/pull/23/changes

[itowlson]

@kate-goldenring I didn't do a release from that because I realised I forgot to update the versions in spin-pluginify.toml (which are what gets used to make the manifests, so they have to match).

I have committed a whole comedy of errors around this update, sorry.

[kate-goldenring]

@itowlson thanks! I see how this change makes it a single bump per trigger instead of in two places where it can get lost