fix: Make isVaultUpdated required on Encryptor

[FrederikBolding]

Explanation

The isVaultUpdated property does not need to be optional on Encryptor. We have two implementations of the Encryptor and they both include isVaultUpdated. This difference between our actual implementations and the type cause type issues in both clients, e.g: https://github.com/MetaMask/metamask-extension/blob/main/app/scripts/messenger-client-init/snaps/snap-controller-init.ts#L126

References

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've communicated my changes to consumers by updating changelogs for packages I've changed
• I've introduced breaking changes in this PR and have prepared draft pull requests for clients and consumer packages to resolve them