Build(deps): update scipy requirement from ~=1.5 to ~=1.6 (#155)

Updates the requirements on [scipy](https://github.com/scipy/scipy) to permit the latest version.
- [Release notes](https://github.com/scipy/scipy/releases)
- [Commits](scipy/scipy@v1.5.0...v1.6.1)

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Matthew Evans <7916000+ml-evs@users.noreply.github.com>

requirements/requirements.txt

@@ -1,5 +1,5 @@
 numpy~=1.20
-scipy~=1.5
+scipy~=1.6
 psutil~=5.8
 pyyaml~=5.4
 pymongo~=3.11