Update root README dependency graph with @metamask/json-rpc-{engine,middleware-stream}

[MajorLift]

Explanation

• Updating root README dependency graph to reflect @metamask/json-rpc-engine and @metamask/json-rpc-middleware-stream migrations.

References

• Partially implements Post-migration cleanup for @metamask/json-rpc-engine #1981
• Partially implements Post-migration cleanup for @metamask/json-rpc-middleware-stream #1982

Changelog

N/A

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 highlighted breaking changes using the "BREAKING" category above as appropriate

[mcmire]

Looks good!