setup.py: Remove API checks for ancient Sage versions

setup.py

@@ -57,31 +57,8 @@ def readfile(filename):
                          extra_compile_args=['-std=c++11'])
     ]
 
-
-## SageMath 8.1 (included in Ubuntu bionic 18.04 LTS) does not have sage.cpython.string;
-## it was introduced in 8.2.
-compile_time_env = {'HAVE_SAGE_CPYTHON_STRING': False,
-                    'HAVE_ADD_COL_UNTYPED_ARGS': False}
-
-print("Checking whether HAVE_SAGE_CPYTHON_STRING...", file=sys.stderr)
-try:
-    import sage.cpython.string
-    compile_time_env['HAVE_SAGE_CPYTHON_STRING'] = True
-except ImportError:
-    pass
-
-## SageMath 8.7 changed the signature of add_col.
-print("Checking whether HAVE_ADD_COL_UNTYPED_ARGS...", file=sys.stderr)
-try:
-    cythonize(Extension('check_add_col_untyped_args',
-                        sources=['check_add_col_untyped_args.pyx'],
-                        include_dirs=sage_include_directories()),
-              quiet=True,
-              include_path=sys.path)
-    compile_time_env['HAVE_ADD_COL_UNTYPED_ARGS'] = True
-except CompileError:
-    pass
-
+compile_time_env = {'HAVE_SAGE_CPYTHON_STRING': True,
+                    'HAVE_ADD_COL_UNTYPED_ARGS': True}
 print("Using compile_time_env: {}".format(compile_time_env), file=sys.stderr)
 
 setup(