ol-webgl-tile-layer doesn't react to opacity anymore (regression in 6.1.2)

[pwuertz]

Describe the bug
Upgrading from release 6.1.1 to 6.1.2 (i.e. commit 974f155) introduced a regression in ol-webgl-tile-layer. Binding an opacity value like <ol-webgl-tile-layer :opacity="value" ...> still works for the initial value, but it seems like changes to value aren't propagated to the layer anymore. The layer opacity stays at its initial level.

Affected version(s)
Dynamic opacity still works in 6.1.1, and stops working in 6.1.2.

To Reproduce
Steps to reproduce the behavior:

• Create a scene with an <ol-webgl-tile-layer :opacity="value" ...>
• Bind value to a slider and modify it

Desktop (please complete the following information):

• Browser: Firefox, Chrome

Additional context
Tested with OpenLayers 9.0 and 9.1