[php-src] Issue #23443: ext/pdo_odbc: infinite loop / 100% CPU when fetching a large nvarchar(max) via MS ODBC Driver 18 — SQLGetData is called with a 1-byte buffer and the loop never makes progress (distinct from GH-21534)

Issue: https://github.com/php/php-src/issues/23443
Author: chep6915

### Description

[pdo_odbc_issue.md](https://github.com/user-attachments/files/31405874/pdo_odbc_issue.md)

[ODBC][45576][...][SQLGetData.c][237]
        Entry:
            Statement = 0x909c88000
            Column Number = 1
            Target Type = 1 SQL_CHAR
            Buffer Length = 1
            Target Value = 0x106bfb860
            StrLen Or Ind = 0x10741a850
[ODBC][45576][...][SQLGetData.c][545]
        Exit:[SQL_SUCCESS_WITH_INFO]
            Buffer = Indicator = -4
            Strlen Or Ind = 0x10741a850 -> -4 (64 bits)

### PHP Version

```plain
PHP 8.5.8 (cli) (built: Jul  1 2026 03:46:27) (NTS)
Copyright (c) The PHP Group
Built by Homebrew
Zend Engine v4.5.8, Copyright (c) Zend Technologies
    with Zend OPcache v8.5.8, Copyright (c), by Zend Technologies
```

### Operating System

macOS 26.5.2 (build 25F84), Apple Silicon / arm64 (Darwin 25.5.0)