Discontinue openSUSE 15.3 and Ubuntu 18.04 builds for EOL

builder/docker-compose.yml

@@ -1,16 +1,4 @@
 services:
-  ubuntu-1804:
-    command: ./build.sh
-    environment:
-      - R_VERSION=${R_VERSION}
-      - R_INSTALL_PATH=${R_INSTALL_PATH}
-      - LOCAL_STORE=/tmp/output
-    build:
-      context: .
-      dockerfile: Dockerfile.ubuntu-1804
-    image: r-builds:ubuntu-1804
-    volumes:
-      - ./integration/tmp:/tmp/output
   ubuntu-2004:
     command: ./build.sh
     environment:
@@ -107,18 +95,6 @@ services:
     image: r-builds:rhel-9
     volumes:
       - ./integration/tmp:/tmp/output
-  opensuse-153:
-    command: ./build.sh
-    environment:
-      - R_VERSION=${R_VERSION}
-      - R_INSTALL_PATH=${R_INSTALL_PATH}
-      - LOCAL_STORE=/tmp/output
-    build:
-      context: .
-      dockerfile: Dockerfile.opensuse-153
-    image: r-builds:opensuse-153
-    volumes:
-      - ./integration/tmp:/tmp/output
   opensuse-154:
     command: ./build.sh
     environment: