Update dependency rules_swift_package_manager to v1.6.0

Author: renovate[bot]

modules/swift/MODULE.bazel

@@ -7,7 +7,7 @@ module(
 bazel_dep(name = "apple_support", version = "1.23.1")
 bazel_dep(name = "rules_proto_grpc", version = "0.0.0.rpg.version.placeholder")
 bazel_dep(name = "rules_swift", version = "3.1.2")
-bazel_dep(name = "rules_swift_package_manager", version = "1.4.0")
+bazel_dep(name = "rules_swift_package_manager", version = "1.6.0")
 
 swift_deps = use_extension("@rules_swift_package_manager//:extensions.bzl", "swift_deps")
 swift_deps.from_package(