MangaDex: migrate to 1.6

[tigeryu8900]

This change is a bit hacky due to Komikku using MangaDex's latestUpdatesRequest and latestUpdatesParse.

Checklist:

• Updated versionCode value in build.gradle.kts
• Updated baseVersionCode in build.gradle.kts (if updated multisrc theme code)
• Referenced all related issues in the PR body (e.g. "Closes #xyz")
• Set the contentWarning configuration in build.gradle.kts appropriately
• Have not changed source names
• Have explicitly kept the id if a source's name or language were changed
• Have tested the modifications by compiling and running the extension through Android Studio
• Have removed web_hi_res_512.png when adding a new extension
• This PR is AI-assisted, I have reviewed the changes manually and confirmed they are not slop

[AwkwardPeak7]

yeah no.... I will ask them to fix the delegated source, till then we can delay mangadex 1.6

[tigeryu8900]

Extlib 1.4 uses latestUpdatesRequest and latestUpdatesParse, and extlib 1.6 uses getLatestUpdates, so we might need to update MangaDex in two stages.

I'm not sure if they can update on their side without breaking MangaDex.

Edit: nevermind, they can check the version

[tigeryu8900]

I created a draft pr on Komikku to support MangaDex 1.6: komikku-app/komikku#1829