Ensure released Mantid version uses a specific released MSlice version

[SilkeSchomann]

Currently, a Mantid nightly uses the current MSlice nightly. This is acceptable, as these versions are not fully tested by design. However, a released version of Mantid always needs to use a specific released version of MSlice. I thought a pin in the conda recipe would ensure this, but apparently not. Until the release of 6.12 we need to find a way to ensure this.

[thomashampson]

The standalone installers will only be able to pick up an mslice version from the main label, because of this line (and the equivalent ones in the macOS and Linux standalone packaging sripts)

mantid/installers/conda/win/create_package.sh

Line 77 in 893609a

--copy --channel $CONDA_CHANNEL --channel conda-forge --channel mantid -y \

It seems like we need to satisfy the following:

• release versions of the conda package mantidworkbench must pin exactly the mslice version, and that version must be on the main label
• release versions of the standalone packages must also be installed with exactly the same mslice version
• nightly/unstable versions of the standalone packages should be able to pick up mslice versions on the nightly label consistently with the conda package mantidworkbench

I think this can be achieved by keeping the mslice pin up to date in the mantidworkbench conda recipe in conjunction with checking the package suffix in the standalone packaging scripts.

[github-actions]

Closed by #38674.