HTML email message cut off when using text size higher than 1.0

### What Happened?

When changing text size to values higher than 1.0, the end of the email message is cut off. This prevents email footers from appearing, for example.

- Changing to values below 1.0 will show extra white space past the email message.
- Changing display scaling to 200% or other values (plus fractional) does not cause this.
- Pinch to zoom with touchpad gesture does not fix the issue
- I have not checked this with plain text emails

### Steps to Reproduce

1. Open Settings -> Desktop -> Text -> Size
2. Change size to any valid value other than 1.0
3. Open Elementary Mail
4. Select an HTML email to open
5. Scroll to the bottom of this email and observe where the email ends within the UI

### Expected Behavior

I expect to see the full email message including footers.

### OS Version

8.x (Circe)

### Session Type

Secure Session (Wayland)

### Software Version

Latest release (I have run all updates)

### Log Output

```shell

```

### Hardware Info

Laptop specs:

Lenovo Thinkpad E14 Gen 6
Hexa-Core AMD Ryzen 5 7535U with Radeon Graphics
AMD® Rembrandt [Radeon 680M]
Screen resolution: 1920x1200

Reproduce the issue through Settings -> Desktop -> Text -> Size, then open an HTML email in Elementary Mail and scroll to its bottom. Compare text sizes above and below 1.0, using the missing footer or extra whitespace as the completion check; no source file or test is identified in the report.

Written by the indexing model from the issue text.