Clean "io/ioutil" .

[yanggangtony]

Signed-off-by: yanggang gang.yang@daocloud.io

/kind cleanup

replaced io/ioutil with "os / io" package.

We should clean all io/util package according the url: ioutil 1.16

[blackpiglet]

@yanggangtony
Thanks for your contribution, but we already made some progress in other PR #5744.
We didn't notice this PR soon enough. Could we trace the "io/ioutil" package replacement in that PR?

[yanggangtony]

@yanggangtony Thanks for your contribution, but we already made some progress in other PR #5744. We didn't notice this PR soon enough. Could we trace the "io/ioutil" package replacement in that PR?

hi, i see another pr 5744 is about the same thing.
you means close this one? i see that one have do the same clean work .

[blackpiglet]

@yanggangtony
Yes. I prefer to do the work in #5744.

[yanggangtony]

@yanggangtony Yes. I prefer to do the work in #5744.

OK, just close these one first.