drop support for scalingo 18 and 20

Author: SebouChu

CHANGELOG.md

@@ -3,6 +3,7 @@ All notable changes to this project will be documented in this file.
 
 ### 2025-10-10
 - Added support for Scalingo-24.
+- Dropped support for Scalingo-18 and Scalingo-20.
 
 ## Scalingo buildpack
 

bin/compile

@@ -59,7 +59,7 @@ esac
 
 # Install correct dependencies according to $STACK
 case "${STACK}" in
-  "scalingo-18" | "scalingo-20" | "scalingo-22" | "scalingo-24")
+  "scalingo-22" | "scalingo-24")
     # the package list is found by using ci:debug then running ldd $GOOGLE_CHROME_BIN | grep not
     # also look here for more packages/notes https://developers.google.com/web/tools/puppeteer/troubleshooting
     PACKAGES="
@@ -91,7 +91,7 @@ case "${STACK}" in
     "
     ;;
   *)
-    error "STACK must be 'scalingo-18, 20 or 22', not '${STACK}'."
+    error "STACK must be 'scalingo-22 or scalingo-24', not '${STACK}'."
 esac
 
 if [ ! -f $CACHE_DIR/PURGED_CACHE_V1 ]; then