Improve error logs for GitBuddy GitHub API failures

[AvdLee]

Instead of:

Exit status of command 'mint run --silent gitbuddy release -l 1.7.5b2622 -b develop --skip-comments --json --use-pre-release --target-commitish build/new-version/1.7.6 --tag-name 1.7.5b2623 --release-title '1.7.5b2623 - Beta'' was 1 instead of 0.
Error: The operation couldn’t be completed. (com.nerdishbynature.octokit error 422.)

We will now get:

Error: GitHub API Request failed (StatusCode: 422): ["RequestKitErrorKey": ["message": Validation Failed, "documentation_url": https://docs.github.com/rest/reference/repos#create-a-release, "errors": <__NSArrayM 0x600001c9a970>(
{
    code = "already_exists";
    field = "tag_name";
    resource = Release;
}
)
]]
Underlying error:
Error Domain=com.nerdishbynature.octokit Code=422 "(null)" UserInfo={RequestKitErrorKey={
    "documentation_url" = "https://docs.github.com/rest/reference/repos#create-a-release";
    errors =     (
                {
            code = "already_exists";
            field = "tag_name";
            resource = Release;
        }
    );
    message = "Validation Failed";
}}

[wetransferplatform]

	Messages
📖	View more details on Bitrise
📖	GitBuddyTests: Executed 57 tests (0 failed, 0 retried, 0 skipped) in 1.134 seconds

Code Coverage Report

Name	Coverage
GitBuddy	0.00%	⚠️

Generated by 🚫 Danger Swift against 54cd65b

[BasThomas]

👌

[wetransferplatform]

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