[cmake] Remove DunePythonRequireVersion.cmake

It was deprecated in Dune 2.7.

cmake/modules/CMakeLists.txt

@@ -26,7 +26,6 @@ install(FILES
   DunePythonFindPackage.cmake
   DunePythonInstallPackage.cmake
   DunePythonMacros.cmake
-  DunePythonRequireVersion.cmake
   DunePythonTestCommand.cmake
   DunePythonVirtualenv.cmake
   DuneSphinxDoc.cmake

cmake/modules/DunePythonCommonMacros.cmake

@@ -67,7 +67,6 @@
 # to explicitly include parts of our build system.
 include(DunePythonFindPackage)
 include(DunePythonInstallPackage)
-include(DunePythonRequireVersion)
 include(DunePythonTestCommand)
 
 # Find the Python Interpreter and libraries

cmake/modules/DunePythonRequireVersion.cmake

-# This module provided functions to implement constraints on the major version of the python interpreter.
-# With Python2 support being dropped from Dune these are not needed anymore.
-
-if(DUNE_PYTHON_FORCE_PYTHON2 OR DUNE_PYTHON_FORCE_PYTHON3 OR DUNE_PYTHON_FORCE_PYTHON_VERSION)
-  message(WARNING "Python 2 support has been dropped from Dune. The variables DUNE_PYTHON_FORCE_PYTHON2, DUNE_PYTHON_FORCE_PYTHON3 and DUNE_PYTHON_FORCE_PYTHON_VERSION variables are not doing anything anymore.")
-endif()
-
-function(dune_python_require_version)
-  message(WARNING "Dune has dropped Python2 support. The function dune_python_require_version is now no-op, is deprecated, and will be removed after Dune 2.7.")
-endfunction()
-
-function(dune_python_force_version)
-  message(WARNING "Dune has dropped Python2 support. The function dune_python_force_version is now no-op, is deprecated, and will be removed after Dune 2.7.")
-endfunction()