Changed Dockerfile to use Pharo VM 10.3.0 (#20)

Author: mtabacman

source/Dockerfile

@@ -11,7 +11,7 @@ RUN set -eu; \
   true
 
 # Copy Pharo Image into base image
-FROM ghcr.io/ba-st/pharo-vm:v10.2.0 as image
+FROM ghcr.io/ba-st/pharo-vm:v10.3.0 AS image
 LABEL org.opencontainers.image.authors="Buenos Aires Smalltalk <[email protected]>"
 WORKDIR /opt/pharo
 USER root