"Target strength" slider snaps to pre-determined amounts, even when values are input manually, making it impossible to add custom values.

Repro steps:
1. Open Terrain scene from attached project.
2. Select terrain from hierarchy and navigate to "paint details" section.
3. Try to enter 0.4 under "Target Strength"
4. Observe how value snaps to closest snap-point (in this case, 3.75)

Expected outcome: no hard snap for this field, consistent with all other fields in the terrain component.

Notes:
- Not a regression, happening in 5.3.1f1.
- Inconsistent behaviour with other sliders in the terrain component.
- Other "target strength" slider in "paint textures" works as expected.