Update maxima package use flags for Gentoo

[dimpase]

makes sure maxima on Gentoo is maxima[ecl], not maxima[sbcl]
See https://bugs.gentoo.org/964693

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[orlitzky]

I don't really care about these suggestions any more, but why bother? Sage needs maxima[ecl] for maxima_lib, but if you want to run maxima yourself outside of sage, you are free to use whatever lisp is your favorite.

The CI probably writes these flags to package.use, but if a normal user runs emerge maxima[-sbcl,ecl], it will build maxima with only ECL support once, and then the next emerge -uDN @world will rebuild maxima just to add back SBCL support (since IUSE=+sbcl is set in the ebuild.)

[dimpase]

for CI (and just for testing) we'd like to have the system install commands right. I stumbled upon this because maxima[sbcl] gives different results for some tests.

[orlitzky]

Ok, SBCL doesn't build on riscv (no bootstrap binaries) so I can't help test any other workarounds.

[dimpase]

@orlitzky
Thanks. By the way, risc-v sbcl apparently can be built, see https://morphykuffour.github.io/linux/riscv/qemu/ubuntu/sbcl/2025/05/06/SBCL-development-on-riscv-architecture.html

[orlitzky]

Oh, nice. Waiting for fedora/debian to do it is how I maintain half of my packages :P