Bump instruments constraint in OTel auto instrumentation

[anuraaga]

Currently, the instruments constraint is the current version

https://github.com/connectrpc/connect-python/pull/163/changes#diff-a4524c6583bac282e8d55f718b73d68361e4f173c175a43a625b1b1592af4c25R20

This allows tests to run right now, however, the instrumentation uses APIs that will be released with 0.9.0. It will need to be bumped after #162 and before any connectrpc-otel release. This issue is just to track that.