gnu: Remove usages of python-setuptools-next and python-setuptools-scm-next.

These are deprecated, and trigger deprecation warnings.

Automated via, manually reverting the two define-deprecated hunks:

  git grep -l python-setuptools-next |
   xargs sed -i 's/python-setuptools-next/python-setuptools/'

  git grep -l python-setuptools-scm-next |
   xargs sed -i 's/python-setuptools-scm-next/python-setuptools-scm/'

Change-Id: Ied5073176cd6578f7524af0deec9182577c1b786

gnu/packages/astronomy.scm

@@ -3764,7 +3764,7 @@ lens models possibly obtained from different modeling codes.")
     (native-inputs
      (list python-pytest
            python-scipy
-           python-setuptools-next
+           python-setuptools
            python-setuptools-scm))
     (propagated-inputs
      (list python-numpy))
@@ -4329,8 +4329,8 @@ tools for astronomers.")
      (list python-cython
            python-numpy
            python-pytest
-           python-setuptools-next
-           python-setuptools-scm-next))
+           python-setuptools
+           python-setuptools-scm))
     (propagated-inputs
      (list python-corsikaio
            python-matplotlib
@@ -4439,7 +4439,7 @@ all the input image headers.")
                        #$(this-package-input "cfitsio") "/lib")))))))
     (native-inputs
      (list python-pytest
-           python-setuptools-next))
+           python-setuptools))
     (inputs
      (list curl
            cfitsio
@@ -5966,8 +5966,8 @@ photometry, segmentations, Petrosian profiling, and Sérsic fitting.")
            python-extension-helpers
            python-pytest-astropy
            python-pytest-xdist
-           python-setuptools-next
-           python-setuptools-scm-next))
+           python-setuptools
+           python-setuptools-scm))
     (propagated-inputs
      (list python-astropy
            python-bottleneck
@@ -6439,7 +6439,7 @@ Pipeline Library, CPL} toolkit, including the CPL plugin interface.")
     (native-inputs
      (list python-pytest-astropy
            python-pytest-mock
-           python-setuptools-next
+           python-setuptools
            python-setuptools-scm))
     (propagated-inputs
      (list python-astropy
@@ -7131,7 +7131,7 @@ end products of specific X-ray observatories.")
                     " and not "))))
     (native-inputs
      (list python-pytest
-           python-setuptools-next))
+           python-setuptools))
     (propagated-inputs
      (list python-astropy
            python-matplotlib

gnu/packages/password-utils.scm

@@ -1472,7 +1472,7 @@ program.")
     (native-inputs
      (list python-pytest-cov
            python-pytest-mock
-           python-setuptools-next))
+           python-setuptools))
     (inputs
      (list password-store python-pyxdg))
     (home-page "https://github.com/languitar/pass-git-helper")

gnu/packages/python-check.scm

@@ -1853,8 +1853,8 @@ are too large to conveniently hard-code them in the tests.")
            #~(modify-phases %standard-phases
                (delete 'sanity-check))))
     (native-inputs
-     (list python-setuptools-next
-           python-setuptools-scm-next))
+     (list python-setuptools
+           python-setuptools-scm))
     (home-page "https://github.com/asdf-format/pytest-asdf-plugin")
     (synopsis "Pytest plugin for testing ASDF schemas")
     (description