blender: don't require python3.7m on darwin

python is currently pointing to the python38, so this patches the
required version to match python version that is provided to the
expression. The m prefix denotes the pymalloc ABI for python 3.7 and
older, but is not provided starting python 3.8.

pkgs/applications/misc/blender/default.nix

@@ -57,6 +57,10 @@ stdenv.mkDerivation rec {
         --replace '${"$"}{LIBDIR}/python' \
                   '${python}'
       substituteInPlace build_files/cmake/platform/platform_apple.cmake \
+        --replace 'set(PYTHON_VERSION 3.7)' \
+                  'set(PYTHON_VERSION ${python.pythonVersion})' \
+        --replace '${"$"}{PYTHON_VERSION}m' \
+                  '${"$"}{PYTHON_VERSION}' \
         --replace '${"$"}{LIBDIR}/python' \
                   '${python}' \
         --replace '${"$"}{LIBDIR}/opencollada' \