tools: update for std.process API changes

tools/update_clang_options.zig

@@ -676,7 +676,6 @@ pub fn main(init: std.process.Init) !void {
 
     const child_result = try std.process.run(arena, io, .{
         .argv = &child_args,
-        .max_output_bytes = 100 * 1024 * 1024,
     });
 
     std.debug.print("{s}\n", .{child_result.stderr});

tools/update_cpu_features.zig

@@ -1987,7 +1987,6 @@ fn processOneTarget(io: Io, job: Job) void {
 
         const child_result = try std.process.run(arena, io, .{
             .argv = &child_args,
-            .max_output_bytes = 500 * 1024 * 1024,
         });
         tblgen_progress.end();
         if (child_result.stderr.len != 0) {