Using cp command on Windows with absolute path malfunctions

It seems this line causes the bug;
https://github.com/kubernetes/kubectl/blob/65639830b2b0e5f6b254d05b911b7676eb7757d2/pkg/cmd/cp/cp.go#L170

**Steps to reproduce**
Execute the command `kubectl cp C:\test.txt [your-pod]:/path/to/file/in/pod -n [namespace]`

**Expected Result**
File should be copied to the /path/to/file/in/pod

**Actual Result**
`failed to copy tar file to pod: error: one of src or dest must be a local file specification`

Start at pkg/cmd/cp/cp.go around line 170 and reproduce the command with a Windows absolute source path: kubectl cp C:\test.txt [your-pod]:/path/to/file/in/pod -n [namespace]. Trace why the source is not recognized as local. Done means the command copies the file to the pod path without the “one of src or dest” error.

Written by the indexing model from the issue text.