Handle almalinux-8 like centos-8

Author: Matthias Koeppe

build/pkgs/_python3.9/distros/fedora.txt

@@ -1,3 +1,3 @@
 python3.9
 python3.9-devel
-# Except on centos-stream-8, where it is called python39 and python3.9-devel; we special-case this in tox.ini
+# Except on centos-stream-8 and almalinux-8, where it is called python39 and python39-devel; we special-case this in tox.ini

tox.ini

@@ -559,7 +559,7 @@ setenv =
     conda:                                                           CONFIG_CONFIGURE_ARGS_1=--with-system-python3=force --with-python=python3
     conda:                                                             EXTRA_SAGE_PACKAGES_5=_bootstrap liblzma bzip2 libffi libpng zlib
 
-    centos-stream-8-python3.9:                                           EXTRA_SYSTEM_PACKAGES=python39 python39-devel
+    {centos-stream,almalinux}-8-python3.9:                             EXTRA_SYSTEM_PACKAGES=python39 python39-devel
     #
     #  - toolchain
     #