Update dependency rules_jvm_external to v6

Author: renovate[bot]

WORKSPACE

@@ -68,9 +68,9 @@ http_archive(
 
 http_archive(
     name = "rules_jvm_external",
-    sha256 = "d31e369b854322ca5098ea12c69d7175ded971435e55c18dd9dd5f29cc5249ac",
-    strip_prefix = "rules_jvm_external-5.3",
-    url = "https://github.com/bazelbuild/rules_jvm_external/releases/download/5.3/rules_jvm_external-5.3.tar.gz",
+    sha256 = "c18a69d784bcd851be95897ca0eca0b57dc86bb02e62402f15736df44160eb02",
+    strip_prefix = "rules_jvm_external-6.3",
+    url = "https://github.com/bazelbuild/rules_jvm_external/releases/download/6.3/rules_jvm_external-6.3.tar.gz",
 )
 
 http_archive(