build/pkgs/exceptiongroup: skip if python >= 3.11

Author: orlitzky

build/pkgs/exceptiongroup/spkg-configure.m4

@@ -0,0 +1,24 @@
+SAGE_SPKG_CONFIGURE([exceptiongroup],[
+  SAGE_PYTHON_PACKAGE_CHECK([exceptiongroup])
+],[
+  # This is another backport package, but not one that is a direct
+  # dependency of sagelib yet. Since it provides python-3.11 features,
+  # it is superfluous when >=python-3.11 is being used. Here we test
+  # for a python minor version component greater than or equal to 11,
+  # and mark this package as "not required" if we succeed.
+  #
+  # See also: importlib_metadata, importlib_resources, typing_extensions
+  #
+  AC_MSG_CHECKING([for >=python-3.11])
+
+  # PYTHON_MINOR is exported by python's spkg-configure.m4
+  AC_REQUIRE([SAGE_SPKG_CONFIGURE_PYTHON3])
+
+  AS_IF([test $PYTHON_MINOR -ge 11],[
+    AC_MSG_RESULT([yes])
+    sage_require_exceptiongroup=no
+  ],[
+    AC_MSG_RESULT([no])
+  ])
+])
+