feat(deploy): use upsertDeployment for image deploys on Houston 2.1.0+

[Simpcyclassy]

Description

Switches the astro deploy --remote image push to use the upsertDeployment GraphQL mutation when connected to Houston 2.1.0+. Older Houston versions continue to use updateDeploymentImage. The variables and call sites are unchanged — releaseName remains the lookup key, now supported on upsertDeployment via the matching houston-api change.

🎟 Issue(s)

PLX-232

🧪 Functional Testing

1. Build a local image and tag it for a deployment registry.
2. Against a Houston < 2.1.0: run astro deploy --remote --image-name <img> --runtime-version <v> <deployment> and confirm the deploy still completes (uses updateDeploymentImage).
3. Against a Houston >= 2.1.0 (with the matching houston-api change deployed): run the same command and confirm the deploy completes (uses upsertDeployment).
4. Pass a non-existent release name to confirm the new clear error message: No deployment exists with releaseName: <name>.

📸 Screenshots

N/A — no UI changes.

📋 Checklist

• Rebased from the main (or release if patching) branch (before testing)
• Ran make test before taking out of draft
• Ran make lint before taking out of draft
• Added/updated applicable tests
• Tested against Astro-API (if necessary).
• Tested against Houston-API and Astronomer (if necessary).
• Communicated to/tagged owners of respective clients potentially impacted by these changes.
• Updated any related documentation

[coveralls-official]

Coverage Report for CI Build 0

Coverage remained the same at 39.653%

Details

• Coverage remained the same as the base build.
• Patch coverage: No coverable lines changed in this PR.
• No coverage regressions found.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

No coverage regressions found.

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Coverage Stats

Relevant Lines:	66078
Covered Lines:	26202
Line Coverage:	39.65%
Coverage Strength:	9.39 hits per line

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💛 - Coveralls

[danielhoherd]

Adds a new version of a mutation. LGTM.