Update build script for apex signing

Description

Update builds scripts for signing apex modules.

Recently we found a vulnerability in /e/OS. As reported in this tweet. We were not properly signing as lineage mentioned in their wiki. So adapt our script for this changes

Issue(s)

https://gitlab.e.foundation/e/os/backlog/-/issues/1893

Test environment

• Install a build on a existing /e/OS device
• Fresh install with bootloader locked
• Fresh install with unlocked bootloader

Test procedures

Run a pipeline build using these branches for your devices

• 1880-t-apex_sign
• 1880-s-apex_sign
• 1880-r-apex_sign

Technical details

Signing our final OTA zip using wiki provided by lineage

https://wiki.lineageos.org/signing_builds#generate-keys-without-a-password

Changes: -

• Sign OTA Zip including apex modules
• Create IMG-*.zip same as before and make sure its working when bootloader/unlocked
• Create QFIL-*.zip same as before and make sure its working when bootloader/unlocked
• Make sure browser doesn't break after signing

Screenshots

Check list

• Self review
• Test procedure explained
• Tested on fresh install
• Tested applied as an update
• License
• Internal documentation
• User documentation