build: Update git archival options to support auto versioning (#1951)

* Update the options in .git_archival.txt to fully support to allow Git archives
  (including the ones generated from GitHub) to support versioning.
   - c.f. scikit-hep/scikit-hep.github.io#250
   - c.f. https://github.com/pypa/setuptools_scm/tree/1b18371fc2fa672f39c758a103c4d12956b5964f#git-archives
* Require 'setuptools_scm>=7.0.1' for the build system to ensure support.
   - Drop addition of 'setuptools_scm[toml]' extra as no longer required.
* Require 'setuptools>=61.0.0' for the build system as v61.0.0 adds support for
  pyproject.toml configuration. This configuration is not currently used by pyhf, but
  it is updated given the recommendation by the Scikit-HEP developer guide.
   - c.f. https://setuptools.pypa.io/en/latest/history.html#v61-0-0

Author: matthewfeickert

.git_archival.txt

@@ -1 +1,4 @@
+node: $Format:%H$
+node-date: $Format:%cI$
+describe-name: $Format:%(describe:tags=true,match=*[0-9]*)$
 ref-names: $Format:%D$

pyproject.toml

@@ -1,6 +1,6 @@
 [build-system]
 # Minimum requirements for the build system to execute.
-requires = ["setuptools>=42.0.0", "setuptools_scm[toml]>=3.4"]
+requires = ["setuptools>=61.0.0", "setuptools_scm>=7.0.1"]
 build-backend = "setuptools.build_meta"
 
 [tool.setuptools_scm]