Specifying a relative profile directory doesn't work with flatpak

[freaktechnik]

Is this a feature request or a bug?

Bug

What is the current behavior?

• Run web-ext with -f flatpak:org.mozilla.firefox and a relative profile directory like -p ./tmp-profile
• Firefox fails to launch - presumably because the profile location is not made absolute when passed as a volume share for the flatpak.

What is the expected or desired behavior?

Firefox gets opened etc.

Version information (for bug reports)

• Firefox version: 106.0.3
• Your OS and version: fedora 36
• Versions:

> node --version && npm --version && npx web-ext --version
v16.14.0
8.3.1
7.3.1