Migration table is not found

**Description**

When running `dbmate up` the migration table is not found thus migrations in the migration directory are re-ran every single time which result in an error.

We currently run dbmate part of a shell script that loops over some values and applies the migrations for each value in the loop.
It looks something like the following:
```
values=$(cat cars)
for value in $values; do
echo "Migrating up '$value' schema"
dbmate \
--url "$DATABASE_URL" \
--migrations-dir "migrations/$value" \
--migrations-table "$value.schema_migrations" \
--no-dump-schema \
--wait \
up
done
```

The `DATABASE_URL` has the following value: `postgresql://atlas:postgres@localhost:5432/atlas?sslmode=disable`

When using **dbmate version 1.6.0**, everything works as expected. When we updated to version 2.X.X, we started seeing the previously described behavior.

By running dbmate in my IDE and setting breakpoints, I was able to trace where the issue is. For Postgres, in the `quotedMigrationsTableNameParts` method, the `quote_ident` function that's being used to add quotations around the schema name are resulting in the table `schema_migrations` not to be found even though it exists. If the query used to find the schema migration tables is adjusted from `select quote_ident(unnest($1::text[]))` to `select unnest($1::text[])` then the schema migrations is correctly found.
This behavior seems to not exist in version 1.6.0

- Version: 2
- Database: Postgres 12 running inside a docker container
- Operating System: macOS

**Steps To Reproduce**

dbmate \
--url "postgresql://atlas:postgres@localhost:5432/atlas?sslmode=disable" \
--migrations-dir "migrations/bmw" \
--migrations-table "bmw.schema_migrations" \
--no-dump-schema \
--wait \
up

the migrations in the migration directory are always ran as if it's the first time dbmate is running

**Expected Behavior**

the migrations that already ran and are in the `schema_migrations` table are not ran and only new migrations run