enable build with Maven 4

[hboutemy]

[INFO] -------------------------------------------------
[INFO] Build Summary:
[INFO]   Passed: 76, Failed: 7, Errors: 0, Skipped: 1
[INFO] -------------------------------------------------
Error:  The following builds failed:
Error:  *  mshade-123/pom.xml
Error:  *  MSHADE-467_parallel-dependency-reduced-pom/pom.xml
Error:  *  MSHADE-285_createTestSourcesJar/pom.xml
Error:  *  MSHADE-340_shadedTestJarArtifactAttached/pom.xml
Error:  *  dep-reduced-pom-exclusions/pom.xml
Error:  *  MSHADE-284_shadeTestJar/pom.xml
Error:  *  MSHADE-105/pom.xml
[INFO] -------------------------------------------------

[Bukama]

Apache Maven 4.0.0-rc-5 (fb3ecaef88106acb40467a450248dfdbd75f3b35)
Maven home: C:\apache-maven-4.0.0-rc-5
Java version: 25.0.2, vendor: Azul Systems, Inc., runtime: C:\Program Files\Zulu\zulu-25
Default locale: de_DE, platform encoding: UTF-8
OS name: "windows 11", version: "10.0", arch: "amd64", family: "winnt"


[INFO] Build Summary:
[INFO]   Passed: 74, Failed: 9, Errors: 0, Skipped: 1
[INFO] -------------------------------------------------
[ERROR] The following builds failed:
[ERROR] *  dep-reduced-pom-exclusions\pom.xml
[ERROR] *  MSHADE-105\pom.xml
[ERROR] *  mshade-123\pom.xml
[ERROR] *  MSHADE-284_shadeTestJar\pom.xml
[ERROR] *  MSHADE-285_createTestSourcesJar\pom.xml
[ERROR] *  MSHADE-340_shadedTestJarArtifactAttached\pom.xml
[ERROR] *  MSHADE-467_parallel-dependency-reduced-pom\pom.xml
[ERROR] *  shading-with-java-8-sources\pom.xml
[ERROR] *  shading-with-release-sources\pom.xml
[INFO] -------------------------------------------------
[WARNING] The following builds were skipped:
[WARNING] *  MSHADE-185\pom.xml

dep-reduced-pom-exclusions

The exclusion on second dependency is missing

Assertion failed: 

assert pom[ns.dependencies][ns.dependency][1][ns.exclusions][ns.exclusion].size() == 1

MSHADE-105

API incompatibility

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-resources-plugin:4.0.0-beta-1:resources (default-resources) on project MSHADE-105-BUNDLE: Execution default-resources of goal org.apache.maven.plugins:maven-resources-plugin:4.0.0-beta-1:resources failed: An API incompatibility was encountered while executing org.apache.maven.plugins:maven-resources-plugin:4.0.0-beta-1:resources: java.lang.NoSuchMethodError: 'java.util.List org.apache.maven.api.services.ProjectManager.getResources(org.apache.maven.api.Project, org.apache.maven.api.ProjectScope)'

mshade-123

API incompatibility

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-enforcer-plugin:1.0:enforce (enforce-maven) on project test: Execution enforce-maven of goal org.apache.maven.plugins:maven-enforcer-plugin:1.0:enforce failed: An API incompatibility was encountered while executing org.apache.maven.plugins:maven-enforcer-plugin:1.0:enforce: java.lang.NoSuchMethodError: 'void org.apache.maven.plugin.PluginParameterExpressionEvaluator.<init>(org.apache.maven.execution.MavenSession, org.apache.maven.plugin.MojoExecution, org.apache.maven.project.path.PathTranslator, org.codehaus.plexus.logging.Logger, org.apache.maven.project.MavenProject, java.util.Properties)'

MSHADE-284_shadeTestJar
MSHADE-285_createTestSourcesJar
MSHADE-340_shadedTestJarArtifactAttached

API incompatibility

[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-jar-plugin:4.0.0-beta-1:test-jar (default) on project mshade-284-parent: Execution default of goal org.apache.maven.plugins:maven-jar-plugin:4.0.0-beta-1:test-jar failed: An API incompatibility was encountered while executing org.apache.maven.plugins:maven-jar-plugin:4.0.0-beta-1:test-jar: java.lang.NoSuchMethodError: 'org.apache.maven.api.Artifact org.apache.maven.api.Project.getPomArtifact()'

MSHADE-467_parallel-dependency-reduced-pom

The exclusion on some dependencies are missing

Assertion failed: 

assert exclusionCount == 5
       |              |
       3              false

shading-with-java-8-sources
shading-with-release-sources

Caused by: java.lang.NullPointerException: Cannot invoke "org.codehaus.plexus.PlexusContainer.lookup(String)" because the return value of "org.apache.maven.execution.MavenSession.getContainer()" is null

[hboutemy]

as expected, after #816 improvement, on 7 failing ITs. we now have only 2:

[INFO] Build Summary:
[INFO]   Passed: 81, Failed: 2, Errors: 0, Skipped: 1
[INFO] -------------------------------------------------
[ERROR] The following builds failed:
[ERROR] *  MSHADE-467_parallel-dependency-reduced-pom/pom.xml
[ERROR] *  dep-reduced-pom-exclusions/pom.xml
[INFO] -------------------------------------------------

[hboutemy]

#820 expected to fix the 2 remaining issues

[gnodet]

I verified locally that #820 fixes the two remaining IT failures reported here.

With the #820 patch applied and running against Maven 4.0.0-rc-5 (fb3ecaef), the full IT suite passes cleanly:

Build Summary:
  Passed: 83, Failed: 0, Errors: 0, Skipped: 1

The single skip is the pre-existing MSHADE-185 (unrelated). No regression on Maven 3.9.16 either.

Once #820 is merged, this PR should be safe to merge — the maven4-enabled: true flag will add 4.0.0-rc-5 to the CI matrix, and all ITs will be green.