Update simbody to a version with SimTK::CableSpan support

[adamkewley]

Fixes issue N/A (@pepbos , @nickbianco )

Brief summary of changes

• Update upstream simbody to a version that includes Scholz2015 wrapping algorithm simbody/simbody#791 (commit: aff36c1c4b4c6020866d3a4c66471e037fcb1ce2 )

Testing I've completed

• None

Looking for feedback on...

N/A

CHANGELOG.md (choose one)

• no need to update because internal, until we start building prototypes on top of it etc. etc.

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This change is 

[adamkewley]

Ulterior motive is that the updated opensim-core main will be propagated to opensim-creator, which might make building prototypes, visualizers, etc. for SimTK::CableSpan easier, if required.

[adamkewley]

It looks like upstream simbody has done something with its libBLAS and now our CI is broken. It'll require some investigation.

[halleysfifthinc]

BLAS link failure is my fault from simbody/simbody#795 and simbody/simbody#796. I've got a fix ( 🤞 ) up at my fork halleysfifthinc/simbody#2 (commit: 4638ee275b29eb7a7f1507617746a2e67a921b73). You should be able to test it here by temporarily updating the GIT_URL and GIT_TAG to the commit of my fix. (Passing CI in my fork or upstream simbody doesn't mean anything, since the issue is at the downstream/link library resolution step.)