[GIT-PULLS] [php-src] PR #23306: Fix parameter name in the convert_uudecode() warning

Pull Request: https://github.com/php/php-src/pull/23306
Author: lacatoire

`convert_uudecode()` declares its parameter as `$string`, but its warning names `$data`:

```
convert_uudecode(): Argument #1 ($data) is not a valid uuencoded string
```

Following the message and calling `convert_uudecode(data: 'x')` raises `Error: Unknown named parameter $data`, while `string:` works. Reproduced on 8.4.22 and 8.5.9.

The message is a literal rather than a generated one, which is why it did not follow the parameter. This is the only place in the tree where a hardcoded `$data` does not match the declared parameter; the other hits (`bzcompress`, `bzdecompress`, `gmp_import`, `http_build_query`) all belong to functions whose parameter really is named `$data`.

Three tests pinned the old wording and are updated in the same commit.

Targeting master rather than a stable branch, since the warning text is observable output.