feat: release Dokku on supported versions of Debian and Raspbian

The policy has always been to only release for supported versions of operating systems, so this change aligns what we release for and how Dokku may be installed.

Folks running unmaintained operating systems should upgrade, as the packages are never guaranteed to exist in the Dokku apt repository.

bootstrap.sh

@@ -12,7 +12,7 @@ set -eo pipefail
 # That's good because it prevents our output overlapping with wget's.
 # It also means that we can't run a partially downloaded script.
 
-SUPPORTED_VERSIONS="Debian [10, 11, 12], Ubuntu [20.04, 22.04, 24.04]"
+SUPPORTED_VERSIONS="Debian [11, 12], Ubuntu [20.04, 22.04, 24.04]"
 
 log-fail() {
   declare desc="log fail formatter"
@@ -193,14 +193,14 @@ install-dokku-from-deb-package() {
       OS_ID="noble"
     fi
   elif [[ "$DOKKU_DISTRO" == "debian" ]]; then
-    OS_IDS=("stretch" "buster" "bullseye" "bookworm")
+    OS_IDS=("bullseye" "bookworm")
     if ! in-array "$OS_ID" "${OS_IDS[@]}"; then
-      OS_ID="bullseye"
+      OS_ID="bookworm"
     fi
   elif [[ "$DOKKU_DISTRO" == "raspbian" ]]; then
-    OS_IDS=("buster" "bullseye")
+    OS_IDS=("bullseye" "bookworm")
     if ! in-array "$OS_ID" "${OS_IDS[@]}"; then
-      OS_ID="bullseye"
+      OS_ID="bookworm"
     fi
   fi