[GIT-PULLS] [php-src] PR #23393: ext/pgsql: fix the class name casing of pg_close_stmt()'s connection

Pull Request: https://github.com/php/php-src/pull/23393
Author: lacatoire

`pg_close_stmt()` declares its connection as `Pgsql\Connection`:

```php
function pg_close_stmt(Pgsql\Connection $connection, string $statement_name): PgSql\Result|false {}
```

The class is `PgSql\Connection`, declared that way a few lines below in the same stub and spelled that way by the other thirty-one references in the generated arginfo. This was the only `Pgsql` left in the extension.

Class name resolution is case-insensitive, so nothing breaks at runtime; what leaks is the declaration. On builds where the function exists (libpq >= 17), `ReflectionParameter::getType()` reports `Pgsql\Connection` for this one function and `PgSql\Connection` for every other. The return type on the same line already says `PgSql\Result`.

`pgsql_arginfo.h` is regenerated: one `ZEND_ARG_OBJ_INFO` line plus the stub hash, and no `Pgsql` remains in the file.

The added test needs no server: it reads the declared types through Reflection, prints `pg_close_stmt()` next to `pg_connect_poll()`, which takes the same non-nullable typed connection, and checks both against the class name. It skips where `pg_close_stmt()` is not compiled in.