Do not interrupt a connection on context cancellation

Interrupting at the connection level (and not at the statement) is an issue if
multiple statements are running concurrently on the same connection – for
example, a read statement can cause a write to fail.

Until we can find a more granular answer to cancelling, the feature is disabled.

Allow text to from blob

Fix doc links

Use Go 1.21

Previous build failed due to incompatible Go.mod.