matrix-js-sdk

7ec0bf69 - Only sign key backup with cross-signing keys when available

Only sign key backup with cross-signing keys when available This changes the key backup setup step to only sign with cross-signing keys when both the public and private keys are already available without prompting. In many cases down these paths, the cross-signing keys either may not exist or may not be accessible. We always sign the key backup with your device key as well, so there is always a route to trust the key backup even if this is skipped. Fixes https://github.com/vector-im/element-web/issues/15230