[maintenance] Fix bc-fips jar hell by marking dependency as compileOnly

Signed-off-by: Jialiang Liang <jiallian@amazon.com>

Author: RyanL1997

datasources/build.gradle

@@ -28,12 +28,8 @@ dependencies {
     implementation ('com.amazonaws:aws-encryption-sdk-java:2.4.1') {
         exclude group: 'org.bouncycastle', module: 'bcprov-ext-jdk18on'
     }
-    // When building with -Pcrypto.standard=FIPS-140-3, bcFips jars are provided by OpenSearch
-    if (FipsBuildParams.isInFipsMode()) {
-        compileOnly "org.bouncycastle:bc-fips:${versions.bouncycastle_jce}"
-    } else {
-        implementation "org.bouncycastle:bc-fips:${versions.bouncycastle_jce}"
-    }
+    // bc-fips is provided by OpenSearch core (ships in lib/ by default since 3.6.0)
+    compileOnly "org.bouncycastle:bc-fips:${versions.bouncycastle_jce}"
 
     testImplementation group: 'junit', name: 'junit', version: '4.13.2'
     testImplementation('org.junit.jupiter:junit-jupiter:5.9.3')