Security issues fixes and github actions update

[mpsonntag]

This PR handles

• security issues in dependency libraries
• an update of the github actions workflow

A docker container has been locally built (git annex 10) and successfully tested against a running local GIN instance (git annex 8).

Dependency library security issues

This PR updates dependencies to fix security issues in the golang.org/x/crypto, golang.org/x/sys, golang.org/x/text libraries.
Some of the library updates require and update from the used (1.15) to a newer (1.19+) version of go. Therefore the project is moved to the currently latest go version 1.20.

Github actions update

The go version change also requires github actions updates. The updates include:

• golang verion bump to 1.20
• github action version bump to v3: Node 14 reaches end of live; github actions v3 upgrade to node 16. For details check here.
• golint has been frozen and deprecated and is removed from the linters job.
• due to the upgrade in golang version multiple deprecation warnings pop up in staticcheck. Until these have been resolved, the staticcheck step is allowed to fail without failing the build.
• the "linter" job now produces a summary to display issues identified via staticcheck or errcheck.

[coveralls]

Pull Request Test Coverage Report for Build 4364593422

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 37.882%

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Totals
Change from base Build 2761455674:	0.0%
Covered Lines:	719
Relevant Lines:	1898

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💛 - Coveralls