Upgrade Spoon from 10.4.2 to 11.5.0 (#363)

Follow-up to #352 (stacked on it; GitHub will retarget to `main` once
#352 merges).

## Problem
Spoon 10.4.2 bundles JDT 3.33, which only accepts compliance levels up
to 19 (`20` throws `Unrecognized option : -20`), so #352 has to cap the
level read from the project's pom at 19.

## Change
- `version.spoon`: 10.4.2 → **11.5.0** (JDT 3.46). It needs a Java 17+
runtime (class files are Java 17), which is fine since the verifier
already targets 20.
- `ComplianceLevel.MAX_SUPPORTED` (and so the default when no pom
declares a version): 19 → **26**, the highest level JDT 3.46 accepts
(`27` throws).

No source changes were needed for the Spoon API.

## Downstream
`vscode-liquidjava/server/pom.xml` declares `spoon-core` directly with
`version.spoon` = 10.4.2. That direct dependency overrides the
verifier's transitive one, so the server should be bumped to 11.5.0
together with the verifier version that includes this change. Otherwise
projects declaring Java 20+ would make the model builder throw there.

## Testing
`mvn test`: 369/369 pass (same as #352).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

Author: CatarinaGamboa

liquidjava-verifier/pom.xml

@@ -257,7 +257,7 @@
 		<version.junit>5.10.0</version.junit>
 		<version.memcompiler>1.3.0</version.memcompiler>
 		<version.commons-text>1.12.0</version.commons-text>
-		<version.spoon>10.4.2</version.spoon>
+		<version.spoon>11.5.0</version.spoon>
 		<version.z3>4.8.17</version.z3>
 		<!-- plugin versions -->
 		<pVersion.compiler>3.8.0</pVersion.compiler>

liquidjava-verifier/src/main/java/liquidjava/api/ComplianceLevel.java

@@ -14,8 +14,8 @@
  */
 public final class ComplianceLevel {
 
-    /** Highest level accepted by Spoon 10.4.2 (JDT 3.33), also used when no pom declares one */
-    public static final int MAX_SUPPORTED = 19;
+    /** Highest level accepted by Spoon 11.5.0 (JDT 3.46), also used when no pom declares one */
+    public static final int MAX_SUPPORTED = 26;
 
     public static int resolve(String... paths) {
         return Arrays.stream(paths).map(path -> fromPom(new File(path).getAbsoluteFile())).flatMap(Optional::stream)