Add build constraint file

Numpy 2.0 doesn't play well with some requirements of our python
packages, i.e. spacy and thinc, used in FormFyxer.

This change adds a build-contraint file, as inspired by
https://thinc.ai/docs/install#extended, which will prevent python from
trying to use numpy 2 when doing isolated builds.

Since this file is best referenced from
`https://raw.githubusercontent.com`, this commit will be merged into
main first, and then a commit that references this file will be used in
`publish/action.yml`.

publish/build-constraints.txt

@@ -0,0 +1,4 @@
+# From https://github.com/explosion/thinc/blob/126ea7f10fe746486c8d5cf00e9e2114492a3c31/build-constraints.txt#L1C1-L2C37
+# With additional fix related to https://github.com/SuffolkLITLab/FormFyxer/issues/135
+# build version constraints for use with wheelwright + multibuild
+numpy>=1.25.0,<2.0.0; python_version>='3.9'