Edits docs (#3908)

Update 6.1.3 release notes to match final notes

Merge pull request #3843 from SasView/3783-polydispersity-fitting-not…

…-available-in-batch-fitting

point to the correct logic

SasView 6.1.2 Flatpak

OS-agnostic path check to see if module is in file path

Merge pull request #3818 from SasView/testing-macos-15-intel-for-6.1.…

…2-release

Release 6.1.2: MacOS Intel build using macos 15

Update sasmodels release number to v1.0.12

Update zenodo DOI

Bump pins of sasmodels, and sasdata.

Merge pull request #3483 from SasView/macos-13

Enable macos13 for 6.1.0 release