VA: Check that maxRemoteValidationFailures is non-negative

[pgporada]

Prevents a panic when the VA config field maxRemoteValidationFailures is set to a negative number by adding validation tags

Fixes #7149

[aarongable]

Couldn't this also be done as a config validation tag here?

[pgporada]

Couldn't this also be done as a config validation tag here?

That's a much better plan. The select validation tags now treat the field as optional due to omitempty which allows it to take its zero value. If the field is present, it will check that it's non-negative with min=0. It appears the only time this field is necessary is when on-prem VA has RemoteVAs configured so I added a required_with=RemoteVAs.

[pgporada]

Govulncheck is failing because we're running on go1.21.3 which contains a CVE for Windows file path parsing - which we don't build for.