Bump go version to go 1.17.8

[umbynos]

Please check if the PR fulfills these requirements

• The PR has no duplicates (please search among the Pull Requests
  before creating one)
• The PR follows
  our contributing guidelines
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)
• UPGRADING.md has been updated with a migration guide (for breaking changes)

• What kind of change does this PR introduce?

Update go version used

• What is the current behavior?

We currently use go 1.16.4

• What is the new behavior?

We currently use go 1.17.8

• Does this PR introduce a breaking change, and is
  titled accordingly?

nope

• Other information:

---

See how to contribute

[umbynos]

I have run the tests locally on linux and it seems there are no regressions with go 1.17

[rsora]

Let's be cautious on this one, I would wait for other tasks to be closed, and also to dig a bit more with testing 🔎

[umbynos]

BTW @silvanocerza finished running local tests on macOS and everything went smooth

[umbynos]

Note for future self: The homebrew version is built with go 1.17 (and not pinned) since 0.20.0 Homebrew/homebrew-core#89858

[silvanocerza]

@rsora @umbynos I think we can merge this, I have been building the arduino-cli with Go 1.17 since it came out and never had any issue connected to it.

[per1234]

These should also be updated to say 1.17:

• https://github.com/arduino/arduino-cli/blob/master/docs/CONTRIBUTING.md#prerequisites
• https://github.com/arduino/arduino-cli/blob/master/docs/CONTRIBUTING.md#local-development

(they were forgotten during the Go 1.14 -> 1.16 transition)