Update QEMU to 7.0 as is enforces stronger RISC-V spec compliance

[axel-h]

Follow-up from seL4/seL4#879

The Debinad/Ubuntu releases do not have the latest version, but using it would force us to improve RISC-V spec compliance.

[lsf37]

Is this a docker container issue? It sounds to me like this is something we should support in the build system/tool chain, not in the containers.

[axel-h]

Well, we have to put it into the container, as the tool/test-chain comes from there in the end. So somehow this is a container issue.

[lsf37]

Put what into the container? I don't think it makes sense to change the qemu version there -- we do not want to drop support for them, even if we do want support newer versions.

Edit: right, I managed to just now see the title of the issue. I do not agree that we should do that.

[Ivan-Velickovic]

Is it realistic to have the CI use both the stable container version of QEMU as well as the latest?

[axel-h]

You can have more than one QEMU in the container, as the binary is quite self-contained. So another layer on top would work or just copying it in for a build/test run from somewhere.

[lsf37]

Having both in there sounds reasonable, I can have a look at that.