Add support to remove tags from metrics being sent to datadog

The terraform-spacelift-datadog module has common tags that are included on every metric

• https://github.com/spacelift-io/terraform-spacelift-datadog?tab=readme-ov-file#common-tags

There is also support for adding extra_tags. What is not possible is to exclude the common_tags .

The idea here it to add a new input such as exclude_tags which would allow a user to reduce the amount of tags being added to the metrics.

Example usage:

exclude_tags = ["run_note", "run_url"]

Ideally, the tags on the metrics would then be extra_tags + common_tags - exclude_tags