Remove support for opensuse

We haven't been testing the distro for a while in CI, e.g. in
Tempest, the jobs on opensuse15 haven't been executed for a year
now.
Therefore the patch removes opensuse support from devstack.

Closes-Bug: #2002900
Change-Id: I0f5e4c644e2d14d1b8bb5bc0096d1469febe5fcc
diff --git a/stack.sh b/stack.sh
index 28576d1..8d450aa 100755
--- a/stack.sh
+++ b/stack.sh
@@ -229,7 +229,7 @@
 
 # Warn users who aren't on an explicitly supported distro, but allow them to
 # override check and attempt installation with ``FORCE=yes ./stack``
-SUPPORTED_DISTROS="bullseye|focal|jammy|f36|opensuse-15.2|opensuse-tumbleweed|rhel8|rhel9|openEuler-22.03"
+SUPPORTED_DISTROS="bullseye|focal|jammy|f36|rhel8|rhel9|openEuler-22.03"
 
 if [[ ! ${DISTRO} =~ $SUPPORTED_DISTROS ]]; then
     echo "WARNING: this script has not been tested on $DISTRO"