chore: auto-update metadata coverage in METADATA_SUPPORT.md [no ci]

Author: svc-cli-bot

METADATA_SUPPORT.md

@@ -4,7 +4,7 @@ This list compares metadata types found in Salesforce v65 with the [metadata reg
 
 This repository is used by both the Salesforce CLIs and Salesforce's VSCode Extensions.
 
-Currently, there are 679/720 supported metadata types.
+Currently, there are 678/720 supported metadata types.
 For status on any existing gaps, please search or file an issue in the [Salesforce CLI issues only repo](https://github.com/forcedotcom/cli/issues).
 To contribute a new metadata type, please see the [Contributing Metadata Types to the Registry](./contributing/metadata.md)
 
@@ -314,7 +314,7 @@ To contribute a new metadata type, please see the [Contributing Metadata Types t
 |ExternalDocStorageConfig|✅||
 |ExternalServiceRegistration|✅||
 |ExternalStoragePrvdConfig|✅||
-|ExtlClntAppCanvasStngs|✅||
+|ExtlClntAppCanvasStngs|❌|Not supported, but support could be added|
 |ExtlClntAppConfigurablePolicies|✅||
 |ExtlClntAppGlobalOauthSettings|✅||
 |ExtlClntAppMobileConfigurablePolicies|✅||