fix(ci): latest v4 groovy 4.0.19 has been silently failing; regress to 4.0.3, the ifarm version

[c-dilks]

running even just groovy --version returns the following, and exits 0

java.lang.NoClassDefFoundError: picocli/CommandLine$ParameterException
	at java.base/java.lang.Class.getDeclaredMethods0(Native Method)
	at java.base/java.lang.Class.privateGetDeclaredMethods(Class.java:3166)
	at java.base/java.lang.Class.getMethodsRecursive(Class.java:3307)
	at java.base/java.lang.Class.getMethod0(Class.java:3293)
	at java.base/java.lang.Class.getMethod(Class.java:2106)
	at org.codehaus.groovy.tools.GroovyStarter.rootLoader(GroovyStarter.java:110)
	at org.codehaus.groovy.tools.GroovyStarter.main(GroovyStarter.java:37)
Caused by: java.lang.ClassNotFoundException: picocli.CommandLine$ParameterException
	at org.codehaus.groovy.tools.RootLoader.findClass(RootLoader.java:180)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:594)
	at org.codehaus.groovy.tools.RootLoader.loadClass(RootLoader.java:148)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:527)
	... 7 more

This PR sets the groovy version to 4.0.3 in the maven.yml workflow, to match the version on ifarm.

[c-dilks]

Validation pipelines are also currently failing, for unrelated reasons (possibly from new GEMC tag).

[c-dilks]

Validation pipelines are also currently failing, for unrelated reasons (possibly from new GEMC tag).

resolved by JeffersonLab/clas12-validation#91