tox.ini (debian-buster): Use IGNORE_MISSING_SYSTEM_PACKAGES=yes

Author: Matthias Koeppe

tox.ini

@@ -227,6 +227,7 @@ setenv =
     ubuntu-mantic:                             IGNORE_MISSING_SYSTEM_PACKAGES=yes
     #
     # https://hub.docker.com/_/debian
+    # debian-buster does not have libfreetype-dev (it only has libfreetype6-dev)
     # debian-bullseye does not have libgiac-dev
     # debian-trixie does not have libbrial-dev
     #
@@ -237,6 +238,7 @@ setenv =
     debian-stretch:   BASE_TAG=stretch
     debian-stretch:                            IGNORE_MISSING_SYSTEM_PACKAGES=yes
     debian-buster:    BASE_TAG=buster
+    debian-buster:                             IGNORE_MISSING_SYSTEM_PACKAGES=yes
     debian-bullseye:  BASE_TAG=bullseye
     debian-bullseye:                           IGNORE_MISSING_SYSTEM_PACKAGES=yes
     debian-bookworm:  BASE_TAG=bookworm