Merge commit 'refs/pull/36256/head' of github.com:sagemath/sage into HEAD

Author: dimpase

.github/workflows/ci-linux-incremental.yml

@@ -83,10 +83,9 @@ jobs:
       tox_system_factors: >-
         ["ubuntu-focal",
          "ubuntu-jammy",
-         "ubuntu-mantic,
+         "ubuntu-mantic",
          "debian-bullseye",
          "debian-bookworm",
-         "ubuntu-mantic,
          "fedora-30",
          "fedora-38",
          "gentoo-python3.11",

build/pkgs/rpy2/spkg-configure.m4

@@ -1,6 +1,6 @@
 SAGE_SPKG_CONFIGURE([rpy2], [
-    sage_spkg_install_rpy2=yes
-  ], [dnl REQUIRED-CHECK
+    SAGE_PYTHON_PACKAGE_CHECK([rpy2])
+], [dnl REQUIRED-CHECK
     AC_REQUIRE([SAGE_SPKG_CONFIGURE_R])
     dnl rpy2 is only needed when there is a usable system R
     AS_VAR_IF([sage_spkg_install_r], [yes], [dnl