`AsyncPGInstrumentor` does not instrument prepared statements

[aleksul]

Describe your environment

OS: macos 26
Python version: Python 3.12
Package version: 0.62b1

What happened?

opentelemetry-instrumentation-asyncpg patches Connection.execute(),
Connection.fetch(), Connection.fetchrow(), and Connection.fetchval().
It does not patch the equivalent methods on PreparedStatement
(PreparedStatement.execute(), .fetch(), .fetchrow(), .fetchval(),
.executemany()).

Any query that is executed through a PreparedStatement object is completely
invisible to the instrumentation - no span is emitted.

Steps to Reproduce

Use prepared statements, either directly or simply by using SQLAlchemy.

Here is a repository with MRE:
https://github.com/aleksul/asyncpg-opentelemetry-prepared-statments-mre

Expected Result

Expected that spans are emitted for prepared statements, similarly to how they are emitted for regular executions.

Actual Result

Spans are not emitted for prepared statements.

Additional context

No response

Would you like to implement a fix?

Yes

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