pkg: Fix dir permission check on Windows

[polyrabbit]

Permissions on Windows is different from *nix. This PR separates them.

@spzala

[cretz]

I would have expected not to do a permission check on dirs in Windows instead of still doing the check and requiring 0777. However, if Windows always returns this on every directory, I suppose the effect is the same. So long as [embedded] etcd now runs on Windows, all good.

[polyrabbit]

AFAIK, I suppose all NTFS file systems return 0777. But that's too much details, keep the scope to Windows is enough for now.

[spzala]

@polyrabbit thanks for verifying the permission and commit title update.
LGTM /cc @xiang90 @gyuho @mitake can you please take a quick look? Thanks!

[spzala]

@cretz hi, can you please take a look to the changes or do a quick test in your env, and see if you are good with them? Thanks!

[cretz]

@spzala - I'll have to setup a simple script to run embedded etcd...may be able to get to it in a few hours, I'll update if I can.

[spzala]

@cretz - sounds great, I really appreciate it, thank you so much!

[cretz]

I have confirmed this works on Windows by simply putting go.etcd.io/etcd/v3@master in go mod and confirming the example at the top of https://pkg.go.dev/go.etcd.io/etcd/v3/embed?tab=doc failed until I added a replace directive to point to this locally cloned branch.

Ideally a Windows CI could be leveraged to save others from this kind of manual verification.

[spzala]

I have confirmed this works on Windows by simply putting go.etcd.io/etcd/v3@master in go mod and confirming the example at the top of https://pkg.go.dev/go.etcd.io/etcd/v3/embed?tab=doc failed until I added a replace directive to point to this locally cloned branch.

Ideally a Windows CI could be leveraged to save others from this kind of manual verification.

@cretz thanks much for verifying it. Will merge this PR later today!