ci: speciy golangci-lint build tags at runtime

[trevorwhitney]

What this PR does / why we need it:

This allows golangci-lint to be run natively on MacOS, which allows it to be integrated into many editors via something like https://github.com/nametake/golangci-lint-langserver.

According to golangci-lint docs

Slice options (e.g. list of enabled/disabled linters) are combined from the command-line and config file.

This means non-linux users have no way of removing the linux and promtail_journal_enabled build tags if they are specified in .golangci.yml. By removing them from there and instead specifying the additional tags needed for linux at runtime (which is done via the Makefile change in this PR), it allows users on all platforms to benefit from the linting in real time.

Checklist

• Reviewed the CONTRIBUTING.md guide (required)
• Documentation added
• Tests updated
• Title matches the required conventional commits format, see here
  • Note that Promtail is considered to be feature complete, and future development for logs collection will be in Grafana Alloy. As such, feat PRs are unlikely to be accepted unless a case can be made for the feature actually being a bug fix to existing behavior.
• Changes that require user attention or interaction to upgrade are documented in docs/sources/setup/upgrade/_index.md
• If the change is deprecating or removing a configuration option, update the deprecated-config.yaml and deleted-config.yaml files respectively in the tools/deprecated-config-checker directory. Example PR