Create proxies for abstract entity classes too in Hibernate ORM

[yrodiere]

Fixes a problem reported by @mzellho (thank you!) here: we abstain from creating entity proxies for abstract classes at build time, but in practice... there is no reason to not create them.

The problem seems to have been introduced by mistake here when adding conditions to prevent the creation of proxies for final classes (which, indeed, simply cannot be proxied). It was made more visible by #49591 which revamped the warnings (and maybe added some?) and removed some fallback behavior that could generate proxies at static init.

[quarkus-bot]

/cc @gsmet (hibernate-orm)

[quarkus-bot]

Status for workflow Quarkus CI

This is the status report for running Quarkus CI on commit 05e0a71.

✅ The latest workflow run for the pull request has completed successfully.

It should be safe to merge provided you have a look at the other checks in the summary.

You can consult the Develocity build scans.

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Flaky tests - Develocity

⚙️ JVM Tests - JDK 17

📦 test-framework/jacoco/runtime

❌ io.quarkus.jacoco.runtime.DataFileWatchTest.waitForDataFileThatNeverAppears - History

• Expecting value to be false but was true - org.opentest4j.AssertionFailedError

org.opentest4j.AssertionFailedError: 

Expecting value to be false but was true
	at io.quarkus.jacoco.runtime.DataFileWatchTest.waitForDataFileThatNeverAppears(DataFileWatchTest.java:208)
	at java.base/java.lang.reflect.Method.invoke(Method.java:569)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)

• Expecting value to be false but was true - org.opentest4j.AssertionFailedError

org.opentest4j.AssertionFailedError: 

Expecting value to be false but was true
	at io.quarkus.jacoco.runtime.DataFileWatchTest.waitForDataFileThatNeverAppears(DataFileWatchTest.java:208)
	at java.base/java.lang.reflect.Method.invoke(Method.java:569)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)

❌ io.quarkus.jacoco.runtime.DataFileWatchTest.waitForPreexistingDataFileThatNeverChanges - History

• Expecting value to be false but was true - org.opentest4j.AssertionFailedError

org.opentest4j.AssertionFailedError: 

Expecting value to be false but was true
	at io.quarkus.jacoco.runtime.DataFileWatchTest.waitForPreexistingDataFileThatNeverChanges(DataFileWatchTest.java:241)
	at java.base/java.lang.reflect.Method.invoke(Method.java:569)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)

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⚙️ JVM Tests - JDK 25

📦 extensions/smallrye-graphql/deployment

❌ io.quarkus.smallrye.graphql.deployment.CompletionStageTest.testSourcePost - History

• 1 expectation failed. Expected status code <200> but was <500>. - java.lang.AssertionError

java.lang.AssertionError: 
1 expectation failed.
Expected status code <200> but was <500>.

	at java.base/jdk.internal.reflect.DirectConstructorHandleAccessor.newInstance(DirectConstructorHandleAccessor.java:62)
	at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:499)
	at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:483)
	at org.codehaus.groovy.reflection.CachedConstructor.invoke(CachedConstructor.java:73)