job: No longer free the job data. It's now done by the exit callback

src/nvim/eval.c

@@ -19085,6 +19085,7 @@ static void on_job_stderr(RStream *rstream, void *data, bool eof)
 static void on_job_exit(Job *job, void *data)
 {
   apply_job_autocmds(job, data, "exit", NULL);
+  free(data);
 }
 
 static void on_job_data(RStream *rstream, void *data, bool eof, char *type)

src/nvim/os/channel.c

@@ -92,7 +92,7 @@ uint64_t channel_from_job(char **argv)
                                 channel,
                                 job_out,
                                 job_err,
-                                job_exit,
+                                NULL,
                                 true,
                                 0,
                                 &status);
@@ -275,11 +275,6 @@ static void job_err(RStream *rstream, void *data, bool eof)
   // TODO(tarruda): plugin error messages should be sent to the error buffer
 }
 
-static void job_exit(Job *job, void *data)
-{
-  // TODO(tarruda): what should be done here?
-}
-
 static void parse_msgpack(RStream *rstream, void *data, bool eof)
 {
   Channel *channel = data;

src/nvim/os/job.c

@@ -408,7 +408,6 @@ static void close_cb(uv_handle_t *handle)
     rstream_free(job->err);
     wstream_free(job->in);
     shell_free_argv(job->proc_opts.args);
-    free(job->data);
     free(job);
   }
 }