unknown function name: set_config(STRING,STRING,BOOLEAN) when using parameters in `CONCAT` function

Nobody has claimed this yet.

* **asyncpg version**: 0.30.0
* **PostgreSQL version**: QuestDB 8.1.4
* **Do you use a PostgreSQL SaaS? If so, which? Can you reproduce
the issue with a local PostgreSQL install?**: -
* **Python version**: 3.12.7
* **Platform**: Linux 6.11.5-arch1-1
* **Do you use pgbouncer?**: no
* **Did you install asyncpg with pip?**: yes
* **If you built asyncpg locally, which version of Cython did you use?**: -
* **Can the issue be reproduced under both asyncio and
[uvloop](https://github.com/magicstack/uvloop)?**: yes

Hello,

I am using `asyncpg` with QuestDB and I am getting an error with this query:

```SQL
SELECT FIRST("value")
FROM "values"
WHERE "type" = CONCAT('X', $1, '-', $2)
```

The error:
```
asyncpg.exceptions._base.UnknownPostgresError: unknown function name: set_config(STRING,STRING,BOOLEAN)
```

It works when sending the same query using libpqxx in C++, so I think this is not a problem with QuestDB.

Start by reproducing the parameterized CONCAT query with asyncpg 0.30.0 against QuestDB 8.1.4 under asyncio and uvloop, then compare it with the reported libpqxx behavior. Done means identifying whether the set_config error comes from asyncpg's query handling or QuestDB compatibility and documenting a confirmed fix or limitation.

Written by the indexing model from the issue text.