Makefile: added nilaway (static analysis tool to detect potential Nil panics in Go code)

[fra98]

Description

This PR adds to the Makefile a command to run nilaway, a static analysis tool to detect potential Nil panics in Go code.
Issue make staticcheck to run the tool.

Note: the project is still under active development so false positives can happen.

[adamjensenbot]

Hi @fra98. Thanks for your PR!

I am @adamjensenbot.
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Make sure this PR appears in the liqo changelog, adding one of the following labels:

• kind/breaking: 💥 Breaking Change
• kind/feature: 🚀 New Feature
• kind/bug: 🐛 Bug Fix
• kind/cleanup: 🧹 Code Refactoring
• kind/docs: 📝 Documentation

[cheina97]

/rebase test=true

[cheina97]

/merge