Use junit-bom to make sure that all dependencies use the correct version (#257)

Author: sugmanue

.gitignore

@@ -25,4 +25,5 @@ bin
 .settings
 
 .java-version
-.ammonite
+.ammonite
+.kiro

build.gradle.kts

@@ -56,7 +56,8 @@ dependencies {
     implementation("software.amazon.smithy:smithy-model:[$smithyVersion, 2.0[")
     implementation("software.amazon.smithy:smithy-syntax:[$smithyVersion, 2.0[")
 
-    testImplementation("org.junit.jupiter:junit-jupiter:5.10.0")
+    testImplementation(platform("org.junit:junit-bom:5.10.0"))
+    testImplementation("org.junit.jupiter:junit-jupiter")
     testImplementation("org.hamcrest:hamcrest:2.2")
 
     testRuntimeOnly("org.junit.platform:junit-platform-launcher")