Deprecate repo in favor of modal-labs/modal-client

[thomasjpfan]

After this we can release a final go tag so users can see all the deprecation warnings.

Linters will catch this warning:

And in my IDE:

For us to migrate:

1. Do a release of the SDKs for modal-client.
2. Merge this PR and manually release just the GO SDK.
3. Archive this repo.

[cursor]

PR Summary

Low Risk
Mostly documentation/metadata and linter-configuration updates to announce deprecation and suppress expected warnings; no runtime logic changes.

Overview
Deprecates this repo’s Go SDK in favor of github.com/modal-labs/modal-client/go, adding prominent migration guidance in the root README.md, modal-go/README.md, and a new modal-go/v0.7.3 entry in CHANGELOG.md.

Adds Go deprecation markers (Deprecated: in modal-go/doc.go and a top-level comment in modal-go/go.mod) and updates modal-go/.golangci.toml to exclude staticcheck deprecation and package comment warnings (e.g., SA1019, ST1000) in targeted paths so the final release can ship cleanly.

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[cursor]

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[mwaskom]

Typo? Or am I missing something?

Suggested change

	Replace all imports of `github.com/modal-labs/libmodal/modal-go` with `github.com/modal-labs/modal-client/g`.
	Replace all imports of `github.com/modal-labs/libmodal/modal-go` with `github.com/modal-labs/modal-client/go`.

[thomasjpfan]

This was a typo. 😅