asyncpg + aiogram is not working

Nobody has claimed this yet.

* **asyncpg version**: 0.25.0
* **PostgreSQL version**: latest
* **Do you use a PostgreSQL SaaS? No
the issue with a local PostgreSQL install?**: No
* **Python version**: 3.8
* **Platform**: MacOS
* **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)?**: I dont know

There is some code abstraction coded with aiogram:

```python
async def check_rights(message: types.Message):
return await bot['db_pool'].fetch_query('SELECT is_admin FROM users WHERE id = $1::varchar(30) and username = $2::varchar(30)',
str(message.chat.id), message.from_user.username)

@bot_dispatcher.message_handler(check_rights, commands=['add_admin'])
async def add_admin(message: types.Message):
print('is_admin!')
```

That's how `bot['db_pool']` is created:

```python
async def on_startup():
db = Database()
bot = Bot(token=token)
bot_dispatcher = Dispatcher(bot)

try:
await db.setup_pool()
except asyncpg.exception.InvalidPasswordError:
logging.ERROR("Username or password if incorrect")
exit(-1)
else:
bot['db_pool'] = db
bot['getMeInfo'] = await bot.get_me()
print(await bot['db_pool'].test())
return bot, bot_dispatcher
```

And database object as well:

```python
class Database(object):
def __init__(self):
if environ.get('DEBUG'):
self.host, self.port, self.database = '127.0.0.1', 5432, 'test'
else:
self.host, self.port, self.database = environ.get('PG_HOST', 'postgres'), environ.get('PG_PORT', 5432), environ.get("PG_DATABASE")

@property
def get_pool(self):
return self.pool

async def setup_pool(self):
self.pool = await create_pool(
user = environ.get('PG_USERNAME'),
password = environ.get('PG_PASSWORD'),
host = self.host, port = self.port,
database = self.database
)

async def fetch_query(self, query: str, *args):
async with self.pool.acquire() as connection:
async with connection.transaction():
return await connection.fetchval(query, *args)

async def test(self):
return await self.fetch_query("select 2 ^ $1", 1)
```

Well if I am creating event loop like this:
```python
loop = new_event_loop()
bot, bot_dispatcher = loop.run_until_complete(on_startup())
```

And starting bot like this:
```python
if __name__ == "__main__":
print(f"[+] Bot started with username: {bot['getMeInfo'].username}")
executor.start_polling(bot_dispatcher, skip_updates=True)
```

I can't execute POOL methods, for example:

```python
async def check_rights(message: types.Message):
return await bot['db_pool'].fetch_query('SELECT is_admin FROM users WHERE id = $1::varchar(30) and username = $2::varchar(30)',
str(message.chat.id), message.from_user.username)
```

Error trace:

```
Task exception was never retrieved
future: exception=InterfaceError('cannot perform operation: another operation is in progress')>
Traceback (most recent call last):
File "/Users/riven/Desktop/Projects/botname/src/venv/lib/python3.8/site-packages/aiogram/dispatcher/dispatcher.py", line 415, in _process_polling_updates
for responses in itertools.chain.from_iterable(await self.process_updates(updates, fast)):
File "/Users/riven/Desktop/Projects/botname/src/venv/lib/python3.8/site-packages/aiogram/dispatcher/dispatcher.py", line 235, in process_updates
return await asyncio.gather(*tasks)
File "/Users/riven/Desktop/Projects/botname/src/venv/lib/python3.8/site-packages/aiogram/dispatcher/handler.py", line 116, in notify
response = await handler_obj.handler(*args, **partial_data)
File "/Users/riven/Desktop/Projects/botname/src/venv/lib/python3.8/site-packages/aiogram/dispatcher/dispatcher.py", line 256, in process_update
return await self.message_handlers.notify(update.message)
File "/Users/riven/Desktop/Projects/botname/src/venv/lib/python3.8/site-packages/aiogram/dispatcher/handler.py", line 107, in notify
data.update(await check_filters(handler_obj.filters, args))
File "/Users/riven/Desktop/Projects/botname/src/venv/lib/python3.8/site-packages/aiogram/dispatcher/filters/filters.py", line 72, in check_filters
f = await execute_filter(filter_, args)
File "/Users/riven/Desktop/Projects/botname/src/venv/lib/python3.8/site-packages/aiogram/dispatcher/filters/filters.py", line 56, in execute_filter
return await filter_.filter(*args, **filter_.kwargs)
File "__main__.py", line 65, in check_rights
return await bot['db_pool'].fetch_query('SELECT is_admin FROM users WHERE id = $1::varchar(30) and username = $2::varchar(30)',
File "/Users/riven/Desktop/Projects/botname/src/database.py", line 33, in fetch_query
return await connection.fetchval(query, *args)
File "/Users/riven/Desktop/Projects/botname/src/venv/lib/python3.8/site-packages/asyncpg/pool.py", line 993, in __aexit__
await self.pool.release(con)
File "/Users/riven/Desktop/Projects/botname/src/venv/lib/python3.8/site-packages/asyncpg/pool.py", line 867, in release
return await asyncio.shield(ch.release(timeout))
File "/Users/riven/Desktop/Projects/botname/src/venv/lib/python3.8/site-packages/asyncpg/pool.py", line 224, in release
raise ex
File "/Users/riven/Desktop/Projects/botname/src/venv/lib/python3.8/site-packages/asyncpg/pool.py", line 214, in release
await self._con.reset(timeout=budget)
File "/Users/riven/Desktop/Projects/botname/src/venv/lib/python3.8/site-packages/asyncpg/connection.py", line 1367, in reset
await self.execute(reset_query, timeout=timeout)
File "/Users/riven/Desktop/Projects/botname/src/venv/lib/python3.8/site-packages/asyncpg/connection.py", line 318, in execute
return await self._protocol.query(query, timeout)
File "asyncpg/protocol/protocol.pyx", line 323, in query
File "asyncpg/protocol/protocol.pyx", line 707, in asyncpg.protocol.protocol.BaseProtocol._check_state
asyncpg.exceptions._base.InterfaceError: cannot perform operation: another operation is in progress
```
`cannot perform operation: another operation is in progress` - Which one? I am doing only 1 request to database 0-o

Start with database.py, especially setup_pool and fetch_query, then trace the on_startup and check_rights entry points shown in the report. Reproduce the polling case and inspect the asyncpg pool acquire and release path; done means explaining which overlapping operation causes the InterfaceError and documenting a verified resolution or minimal reproduction.

Written by the indexing model from the issue text.