Update composer Docker tag to v2.4.3

| datasource | package  | from  | to    |
| ---------- | -------- | ----- | ----- |
| docker     | composer | 2.4.2 | 2.4.3 |


Signed-off-by: Renovate Bot <[email protected]>

Author: renovate[bot]

Dockerfile

@@ -1,6 +1,6 @@
 # Aliasing base images, so we can change just this, when needing to upgrade or pull base layers
 FROM ubuntu:20.04 AS base-distro
-FROM composer:2.4.2 AS composer
+FROM composer:2.4.3 AS composer
 
 
 FROM base-distro AS install-markdownlint