rules_spring springboot requires @bazel_tools//tools/jdk:singlejar usage

[sfc-gh-jlambert]

We need to use a different target for the singlejar tool but it is fixed to @bazel_tools//tools/jdk:singlejar in https://github.com/salesforce/rules_spring/blob/main/springboot/springboot.bzl#L596C1-L602C11 :

        cmd = "$(location @rules_spring//springboot:springboot_pkg.sh) " +
              "$(location @bazel_tools//tools/jdk:singlejar) " + boot_app_class + " " + boot_launcher_class +
              " $(JAVABASE) " + name + " " + str(deps_use_starlark_order) + " " + str(include_git_properties_file) + " $@ $(SRCS)",
        tools = [
            "@rules_spring//springboot:springboot_pkg.sh",
            "@bazel_tools//tools/jdk:singlejar",
        ],

it would be nice if this was a parameter to the method instead so we don't have to do a local_override patch

(there might be an alternative solution involving the jar_toolchains parameter but i couldn't figure it out)