Run golangci-lint with GOOS=linux/darwin/windows

[xzfc]

Description

Currently, our CI doesn't check non-linux platform-specific code. Checking these files may be useful for those who use non-Linux OS as their dev environment.

This PR enables checks for Windows-only and macOS-only files by running GOOS=windows golangci-lint and GOOS=darwin golangci-lint on Ubuntu.

An alternative option is to run this action on windows-latest and macos-lates natively as proposed in the doc, but it fails on Windows due to the path separators difference in exclude-rules in .golangci.yml (see golangci/golangci-lint#1398).

So, this PR solves the issue completely for darwin (i.e. you could run golangci-lint on macOS without errors), and partially for Windows (i.e. Windows-specific files like grpc_utils_windows.go are linted, but golangci-lint is still not usable on Windows).

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Also, this PR removes an unused function GetInode(). The reason is that the linter complains about the Windows implementation of this function.

pkg/tools/fs/inode_windows_amd64.go:38:17: G103: Use of unsafe calls should be audited (gosec)
	ptr := uintptr(unsafe.Pointer(stat))

As I can see in the code, it casts a pointer to some internal data structure into an integer and treats it as an inode number. I don't think this would produce any meaningful result. And I am not sure how to properly fix this function on Windows since there are no inode numbers in Windows. But since this function isn't used anywhere except an archived repo cmd-nsc-proxy, I've deleted it.

Issue link

How Has This Been Tested?

• Added unit testing to cover
• Tested manually
• Tested by integration testing
• Have not tested

Types of changes

• Bug fix
• New functionallity
• Documentation
• Refactoring
• CI

[denis-tingaikin]

@xzfc Should we consider non-linux linter running on CI?

[xzfc]

I'd think it would be an overkill.

An option to lint all files regardless of the platform was proposed in golangci/golangci-lint#1646, but not implemented.
Other options are to run golangci-lint multiple times with different flags (e.g. golangci-lint --build-tags linux && golangci-lint --build-tags windows) or to introduce an additional all tag to all platform-specific code (e.g. // +build linux all).

[denis-tingaikin]

(e.g. golangci-lint --build-tags linux && golangci-lint --build-tags windows) or to introduce an additional all tag to all platform-specific code (e.g. // +build linux all).

Could you please add a step for golangci job with non linux tag?

[xzfc]

Could you please add a step for golangci job with non linux tag?

Done, see the updated PR description.