Refer to the SingleJar "executable" instead of "deploy jar."

I don't think it's been a deploy jar in any environment for a while, and whatever it is, I think we run it directly as a executable.

PiperOrigin-RevId: 839725877
Change-Id: I93ae2cf54cbbfadac153d99c12e9f6f066d50da2

Author: cpovirk

src/main/java/com/google/devtools/build/lib/starlarkbuildapi/java/JavaToolchainStarlarkApiProviderApi.java

@@ -47,7 +47,7 @@ public interface JavaToolchainStarlarkApiProviderApi extends StructApi {
   @StarlarkMethod(name = "label", doc = "The toolchain label.", structField = true)
   Label getToolchainLabel();
 
-  @StarlarkMethod(name = "single_jar", doc = "The SingleJar deploy jar.", structField = true)
+  @StarlarkMethod(name = "single_jar", doc = "The SingleJar executable.", structField = true)
   FilesToRunProviderApi<? extends FileApi> getSingleJar();
 
   @StarlarkMethod(