Thread panel filter ("Show: My threads") resets to "All threads" after opening a thread and going back

### Steps to reproduce

1. Open a room that contains threads.
2. Open the **Threads** panel on the right.
3. Change the filter dropdown to **Show: My threads**.
4. Click a thread to open it.
5. Click the back arrow to return to the thread list.

### Outcome

#### What did you expect?

The filter should still be set to **Show: My threads** when returning to the thread list, so I can continue reviewing my threads one by one.

#### What happened instead?

The filter is silently reset to **Show: All threads** every time I come back from a thread. This means I have to re-select **My threads** between every single thread I open, which makes reviewing my own threads in a busy room extremely tedious.

### Operating system

_No response_

### Browser information

_No response_

### URL for webapp

_No response_

### Application version

Element Web Pro version: 1.12.16

### Homeserver

ESS Pro 26.5.0+2bd8a21570ad

### Will you send logs?

I asked

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Note: this is similar in spirit to #21735 (scroll position of the thread list being reset on the same navigation), but covers the filter selection rather than scroll state.