fix: prevent SO in methodMissing

When using nested configurations, sometimes (haven't figured out when
exactly) the following exception appears:

```
Cause: java.lang.StackOverflowError
    at
com.avast.gradle.dockercompose.ComposeExtension.methodMissing(ComposeExtension.groovy:40)
    at
org.gradle.internal.classpath.CallInterceptingMetaClass.lambda$invokeMethod$5(CallInterceptingMetaClass.java:185)
    at
org.gradle.internal.classpath.CallInterceptingMetaClass.invokeIntercepted(CallInterceptingMetaClass.java:244)
    at
org.gradle.internal.classpath.CallInterceptingMetaClass.invokeMethod(CallInterceptingMetaClass.java:185)
    at
com.avast.gradle.dockercompose.ComposeExtension.methodMissing(ComposeExtension.groovy:60)
    at
org.gradle.internal.classpath.CallInterceptingMetaClass.lambda$invokeMethod$5(CallInterceptingMetaClass.java:185)
    at
org.gradle.internal.classpath.CallInterceptingMetaClass.invokeIntercepted(CallInterceptingMetaClass.java:244)
    at
org.gradle.internal.classpath.CallInterceptingMetaClass.invokeMethod(CallInterceptingMetaClass.java:185)
    at
com.avast.gradle.dockercompose.ComposeExtension.methodMissing(ComposeExtension.groovy:60)
...
```

Where the first invocation of `methodMissing` is with
`name=myCustomNestedConfigurationName` and all further invocations are
with `name=getOrCreateNested` and
`args=[myCustomNestedConfigurationName]`.

So I assume this is an issue due to the gradle 9 (and therefore groovy-4
vs. groovy-3) update. Probably similar issue as in #492.

Refs: #492

Author: simschla

src/main/groovy/com/avast/gradle/dockercompose/ComposeExtension.groovy

@@ -12,7 +12,7 @@ abstract class ComposeExtension extends ComposeSettings {
 
     private HashMap<String, ComposeSettings> settings = [:]
 
-    private ComposeSettings getOrCreateNested(String name) {
+    ComposeSettings getOrCreateNested(String name) {
         settings.computeIfAbsent(name, { cloneAsNested(name) })
     }