Loading a single time step data does not change number of frames to 1

When loading a single timestep data, ParaView still displays multiple times available in the toolbar and in the time manager.

SingleTs.zip is a sphere and a single timestep with time value 42.

Issue #22744 (closed) also provides a python plugin to reproduce.

This seems to be an old behavior.

	master (near 5.12)	5.11	5.8
defaults
animation view	[0, 1], 10 values	same	same
toolbar	combobox with 10 values	line edit, display 0	line edit, display 0
load single ts
info panel	ok : one ts, value 42	same	same
toolbar	42, 10 timesteps in [42, 43]	line edit on 42	line edit on 0
anim view	[42, 43], 10 ts	[42, 43], 10 ts	[0, 1], 10 ts

So:

• ParaView has 10 timesteps by default in the animation scene. Not sure it is the right choice here.
• Loading a single time step data does not override the number of frames. This is more likely a bug.

Some related issues: #19777 (closed) #21477 (closed) #22369 #22744 (closed)