filterDependencies returns the full input set when no excludes are configured, polluting verbose output

## Summary

`dependency:analyze -Dverbose` prints every dependency in **both** the warning section and the "Ignored" section when no `ignoredDependencies` are configured. The "Ignored" section should be empty (or omitted) in this case.

## Root cause

`AbstractAnalyzeMojo.filterDependencies()` at [line 563](https://github.com/apache/maven-dependency-plugin/blob/09e97e39d8994f8f4f965da856ccc699f70e4cb6/src/main/java/org/apache/maven/plugins/dependency/analyze/AbstractAnalyzeMojo.java#L563) returns the full input `artifacts` set when `excludes` is null or empty:

```java
if (excludes == null || excludes.length == 0) {
return artifacts;
}
```

The method's contract is: given a source set and exclude patterns, remove artifacts that **match** an exclude pattern from the source (via `Iterator.remove()`) and **return the removed (excluded) artifacts** in a new set. When no patterns are given, nothing can match, so the method should return an empty set — nothing was excluded. Returning the full `artifacts` set instead tells every caller "everything was excluded."

This affects **all 8 call sites** in the `analyze` goal (lines 363, 365, 367, 368, 369, 372, 374, 375). With default configuration (no `ignoredDependencies`, `ignoredUsedUndeclaredDependencies`, etc. set), every artifact flows into the corresponding `ignored*` set, and with `-Dverbose` the same artifacts appear duplicated under both the warning and ignored sections.

The mutation loop (`it.remove()`) is correctly skipped in this path, so the real warning output is not suppressed — but the ignored section is filled with noise.

## To reproduce

[reproducer-verbose-duplicate.tar.gz](https://github.com/apache/maven-dependency-plugin/releases/download/reproducer-verbose-duplicate/reproducer-verbose-duplicate.tar.gz)

Extract and rebuild the plugin from source:

```bash
git clone https://github.com/apache/maven-dependency-plugin.git
cd maven-dependency-plugin
mvn -DskipTests '-Dmaven.compiler.release=' install
cd ..
tar xzf reproducer-verbose-duplicate.tar.gz
cd dep-analyze-verbose-repro
mvn org.apache.maven.plugins:maven-dependency-plugin:3.11.0:analyze -Dverbose
```

Observe that `commons-lang3` and `commons-text` each appear in **both** the warning section and the ignored section — even though no `ignoredDependencies` is configured.

## Expected behavior

With no `ignoredDependencies` configured, the "Ignored" sections should be not printed at all.

```
[INFO]
[INFO] --- dependency:3.11.0:analyze (default-cli) @ dep-analyze-verbose-repro ---
[WARNING] Used undeclared dependencies found:
[WARNING] org.apache.commons:commons-lang3:jar:3.12.0:compile
[WARNING] class org.apache.commons.lang3.StringUtils
[WARNING] Unused declared dependencies found:
[WARNING] org.apache.commons:commons-text:jar:1.10.0:compile
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
```

## Actual output

```
[INFO]
[INFO] --- dependency:3.11.0:analyze (default-cli) @ dep-analyze-verbose-repro ---
[WARNING] Used undeclared dependencies found:
[WARNING] org.apache.commons:commons-lang3:jar:3.12.0:compile
[WARNING] class org.apache.commons.lang3.StringUtils
[WARNING] Unused declared dependencies found:
[WARNING] org.apache.commons:commons-text:jar:1.10.0:compile
[INFO] Ignored used undeclared dependencies:
[INFO] org.apache.commons:commons-lang3:jar:3.12.0:compile
[INFO] Ignored unused declared dependencies:
[INFO] org.apache.commons:commons-text:jar:1.10.0:compile
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
```

## Proposed fix

The fix is a one-line change in `filterDependencies`:

```java
// line 563 of AbstractAnalyzeMojo.java
if (excludes == null || excludes.length == 0) {
return Collections.emptySet();
}
```

This returns an empty set when no exclude patterns are provided, correctly communicating "nothing was excluded" to all callers.