JsCore: currently no support for 16k page alignment

[stephg]

The current setup grabs JsCore AAR from NPM and uses last published release 250231.0.0.

But the latest JsCore is not released to NPM anymore and can be fetched from maven central directly:
https://mvnrepository.com/artifact/io.github.react-native-community/jsc-android/2026004.0.1

Release 2026004.0.1 is already 16k page aligned, see:
react-native-community/jsc-android-buildscripts#184

So looks like all the download-jsc, jsc and jsc-intl stuff can be dropped and the README.md updated accordingly.

[amraamandal]

Giving warning that "The native library arm64-v8a/libjsc.so (from com.github.fast-development.android-js-runtimes:fastdev-jsruntimes-jsc:0.3.6) is not 16 KB aligned"