feat!: remove KeyringVersion + simplify KeyringRequestWithoutOrigin logic

[ccharly]

Replace KeyringVersion support with a simpler solution, introducing a new KeyringRequestWithoutOrigin which is more explicit and not really tied to any "keyring versions" (as we plan to re-use versioning with the introduction of the unified keyring API)

This will allow to re-use a proper versioning of the keyring with the introduction of keyring capabilities.

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Note

Simplifies compatibility by removing version gating and using an explicit request shape for legacy Snaps.

• Remove KeyringVersion and related helpers; delete versions.ts and associated tests; drop export * from './versions'
• Add KeyringRequestWithoutOrigin structs and toKeyringRequestWithoutOrigin; update compatibility exports and tests
• Rename submitRequestV1 to submitRequestWithoutOrigin in the internal snap client and tests
• In SnapKeyring, replace keyring-version branching with a platform check using PLATFORM_VERSION_FOR_KEYRING_REQUEST_WITH_ORIGIN; call submitRequest when origin is supported, else submitRequestWithoutOrigin

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