chore: drop jmustache dependency until it is fully audited (AIC-2661)

Remove the Mustache templating dependency from the foundation module. It will
be added in a later step (AIC-2662) once the license / maintenance / transitive
-dependency audit is complete. The module's published POM now declares only the
base SDK dependency.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: ctawiah

lib/sdk/server-ai/build.gradle

@@ -44,11 +44,10 @@ ext {
 ext.versions = [
     // The *lowest* version of the base SDK we are compatible with. LDClientInterface
     // appears in this library's public signature, so it is exposed as an `api` dependency.
-    "sdk": "7.14.0",
-    // jmustache: lightweight Mustache implementation used for AI Config message/instruction
-    // interpolation. Dependency audit (AIC-2661): BSD 2-Clause license, actively maintained,
-    // ships as a single self-contained jar with no transitive runtime dependencies.
-    "jmustache": "1.16"
+    "sdk": "7.14.0"
+    // NOTE: a Mustache templating dependency (for AI Config message/instruction interpolation)
+    // will be added in a later step once it has been fully audited (license / maintenance /
+    // transitive deps). See AIC-2662.
 ]
 
 ext.libraries = [:]
@@ -57,10 +56,6 @@ dependencies {
     // Exposed on the public API surface (LDClientInterface), therefore `api` not `implementation`.
     api "com.launchdarkly:launchdarkly-java-server-sdk:${versions.sdk}"
 
-    // Templating engine for Mustache interpolation. Kept as `implementation` so it is not
-    // leaked onto consumers' compile classpath.
-    implementation "com.samskivert:jmustache:${versions.jmustache}"
-
     testImplementation "org.hamcrest:hamcrest-all:1.3"
     testImplementation "junit:junit:4.13.2"
     testImplementation "org.mockito:mockito-core:3.12.4"