Plugin is not compatible with JDKs (like temurin) which support changes of JEP 493 (do not include jmods folder)

### Affected version

3.0.0-SNAPSHOT (current master)

### Bug description
Due the changes of JEP 493 (Java 24) some JDK, for example Temurin, do not ship a JMOD folder anymore. The plugin relies on this folder.

---------------------
Old description

All IT are failing on master

(win 11, Java 25, with Admin rights)

```
D:\Github\Maven\maven-jmod-plugin>mvn -V
Apache Maven 4.0.0-rc-5 (fb3ecaef88106acb40467a450248dfdbd75f3b35)
Maven home: C:\apache-maven-4.0.0-rc-5
Java version: 25, vendor: Eclipse Adoptium, runtime: C:\JDK\Java25
Default locale: de_DE, platform encoding: UTF-8
OS name: "windows 11", version: "10.0", arch: "amd64", family: "winnt"
```

```
[ERROR]
[INFO] -------------------------------------------------
[INFO] Build Summary:
[INFO] Passed: 0, Failed: 18, Errors: 0, Skipped: 0
[INFO] -------------------------------------------------
[ERROR] The following builds failed:
[ERROR] * base-config-cmds\pom.xml
[ERROR] * base-config-headerfiles\pom.xml
[ERROR] * base-config-legalnotices\pom.xml
[ERROR] * base-config-libs\pom.xml
[ERROR] * base-config\pom.xml
[ERROR] * base-it\pom.xml
[ERROR] * describe-base-config\pom.xml
[ERROR] * describe-plain\pom.xml
[ERROR] * list-base-config\pom.xml
[ERROR] * list-plain\pom.xml
[ERROR] * mjmod-20-set-main-class\pom.xml
[ERROR] * mjmod-23-path-must-be-dir\pom.xml
[ERROR] * mjmod-8-generate-jmod-in-other-project\pom.xml
[ERROR] * non-default-config-cmds\pom.xml
[ERROR] * non-default-config-headerfiles\pom.xml
[ERROR] * non-default-config-legalnotices\pom.xml
[ERROR] * non-default-config-libs\pom.xml
[ERROR] * non-default-config\pom.xml
```

Most seen errors

```
assert artifact.isFile()
| |
| false

assert listLines == resourceNames
| | |
[] | ['conf/config.test', 'classes/module-info.class', 'classes/myproject/HelloWorld.class']
false

assert expectedDescriptorLines == describeLines
| | |
| | []
| false
['org.apache.maven.plugins.jmod.it.first@99.0', 'exports myproject', 'requires java.base']

[INFO] java.lang.AssertionError: target file is missing or a directory.. Expression: (artifact.exists() && artifact.isFile())
```

Start by running the integration tests listed in the issue and inspect where the plugin assumes that the JDK contains a jmods folder. Compare the behavior with a Temurin JDK affected by JEP 493. Done means the reported integration tests pass and the missing-artifact, resource-list, and descriptor assertions succeed.

Written by the indexing model from the issue text.