Change to remove ubuntu focal references from c++ image templates (#344)

Co-authored-by: Álvaro Rausell Guiard <[email protected]>

Author: Kaniska244

src/cpp-mariadb/devcontainer-template.json

@@ -1,6 +1,6 @@
 {
     "id": "cpp-mariadb",
-    "version": "3.0.2",
+    "version": "3.0.3",
     "name": "C++ & MariaDB",
     "description": "Develop C++ applications on Linux. Includes Debian C++ build tools.",
     "documentationURL": "https://github.com/devcontainers/templates/tree/main/src/cpp-mariadb",
@@ -14,8 +14,7 @@
                 "debian-12",
                 "debian-11",
                 "ubuntu-24.04",
-                "ubuntu-22.04",
-                "ubuntu-20.04"
+                "ubuntu-22.04"
             ],
             "default": "debian-11"
         },

src/cpp/devcontainer-template.json

@@ -1,6 +1,6 @@
 {
     "id": "cpp",
-    "version": "3.0.2",
+    "version": "3.0.3",
     "name": "C++",
     "description": "Develop C++ applications on Linux. Includes Debian C++ build tools.",
     "documentationURL": "https://github.com/devcontainers/templates/tree/main/src/cpp",
@@ -14,8 +14,7 @@
                 "debian-12",
                 "debian-11",
                 "ubuntu-24.04",
-                "ubuntu-22.04",
-                "ubuntu-20.04"
+                "ubuntu-22.04"
             ],
             "default": "debian-11"
         },