Support new architectures on the download pages for M2 and onward

I'm not sure whether on this page

https://www.eclipse.org/downloads/

that the right architecture is automatically shown:

If it's not automatically known, we should offer the choice.

For m2 on this type of page as current for m1

https://www.eclipse.org/downloads/packages/release/2024-12/m1

there should be more architectures supported, specifically for these places:

There should additionally be Windows AArch64 installers and packages and Linux riscv64 installers and packages.

Note that I rebuilt the installers after M2 so that they include both new architectures:

https://download.eclipse.org/oomph/epp/installer-index.xml

That's why the links are M3 but these should be used for M2 and later when I build for M3 these links will be M4. Anyway, these are the two new installers for which there should be links:

Similarly, for M2 EPP has new links for each package

https://download.eclipse.org/justj/?file=technology/epp/downloads/release/2024-12/M2