[10.10-maintenance] gulpfile.js - remove gconf2 requirement

[nerdCopter]

• issue came up again in discord for Fedora
• uncertain if this is acceptable/proper for all distributions.
• needs testing
• built and installed fine on Debian 12 that already has both gconf2 and dconf installed.
• need for this is debatable.

ref: #3969
#2950

[nerdCopter]

@pitts-mo, @hegelocampus, welcome to test the above builds (#4114 (comment)).

[SuperPi911]

Still needs libgconf-2-4 , the deb package is not installable in linuxmint 22/ ubuntu 24.04

[nerdCopter]

okay, shallow investigation: seems to be a gulp-debian dependency which is alrady latest version 0.3.2 at 2 yrs old.
will investigate further later, probably less likely to fix as PWA https://app.betaflight.com is the now and future.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[nerdCopter]

added dconf as a dependency and updated nw-builder to version 3.8.6 which is the last version that does not require additional changes.
(technically 4.8.1 is the latest nw-builder version, but many modifications would be required to build.)

if this does not work, then i will likely not make more effort.

[github-actions]

Do you want to test this code? Here you have an automated build:
Betaflight-Configurator-Android
Betaflight-Configurator-Linux
Betaflight-Configurator-macOS
Betaflight-Configurator-Windows
WARNING: It may be unstable and result in corrupted configurations or data loss. Use only for testing!

[nerdCopter]

Tested bacb72f1successful on new Fedora Xfce 40 Virtual-Machine: (requires usual udev rules, etc.)

[nerdCopter]

:( fails for new XUbuntu 24.04 VM