Firefox user-agent needs to be kept up-to-date or pages will lock out the users or present false outdated browser warnings
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### Describe your issue
Firefox user-agent needs to be kept up-to-date or pages will lock out the users or present false outdated browser warnings. It seems like currently that's not the case.
#### What's the expected behaviour?
The firefox user-agent uses the latest stable version of Android whenever a new one comes out, with the latest stable version of Firefox available for Android, whenever that comes out.
#### What's the current behaviour?
It's stuck at something old. Some pages don't like it, to see it visit some of the websites that show error pages for old browser versions and/or weird giant security warnings and upgrade notices (but on legitimate websites and not done as a scam, but as legitimate but misguided concern).
#### How to reproduce your issue?
Check about:support which lists the user-agent.
### What device are you using?
Device is likely irrelevant. I'm using the PinePhone Allwinner 3GB RAM variant.
### On what postmarketOS version did you encounter the issue?
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Replace space inside `[ ]` with `x` to fill the checkbox
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* [ ] edge (`master` branch)
* [ ] `v23.12`
* [x] `v23.06` (supported until 2024-01-18)
* [x] I confirm that the issue still is present after running `sudo apk upgrade -a` (yes I actually made sure)
### On what environment did you encounter the issue?
#### Environments
* [ ] GNOME Shell on Mobile
* [x] Phosh
* [ ] Plasma Mobile
* [ ] Sxmo (Wayland/Sway) **Please post the output of `sxmo_version.sh`**
* [ ] Other: **Please fill out**
### How did you get postmarketOS image?
* [ ] from https://images.postmarketos.org
* [ ] I built it using pmbootstrap
* [ ] It was preinstalled on my device
### What's the build date of the image? (in yyyy-mm-dd format)
very old
### Additional information
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issue