Add CI to check for vulnerabilities affecting Go code

[fxamacker]

Issue To Be Solved

We should automatically check for vulnerabilities that affect Go code.

Suggested Solution

Add GitHub Actions workflow to use govulncheck.

According to govulncheck docs:

Govulncheck reports known vulnerabilities that affect Go code. It uses static analysis of source code or a binary's symbol table to narrow down reports to only those that could affect the application.

By default, govulncheck makes requests to the Go vulnerability database at https://vuln.go.dev. Requests to the vulnerability database contain only module paths, not code or other properties of your program.

More info at:

• Go Vulnerability Management: https://go.dev/security/vuln
• govulncheck [mirror]: https://github.com/golang/vuln

[fxamacker]

Closing this for reasons mentioned in feedback to PR #294.