(feature): Replace grafana-agent with opentelemetry-collector

[Abuelodelanada]

This PR replaces grafana-agent with otelcol in COS terraform module.

Closing #70 since it is based in the refactored cos module.

How to test it:

Create the buckets in a S3 and run:

terraform init --upgrade

terraform apply -var='s3_secret_key=secret-key' -var='s3_access_key=access-key' -var='s3_endpoint=http://192.168.1.127' \
-var='loki_bucket=loki' -var='model=cos' -var='mimir_bucket=mimir' -var='tempo_bucket=tempo' -var="mimir_coordinator={units=1}" -var="loki_coordinator={units=1}" -var="tempo_coordinator={units=1}" -var="channel=2/edge" -var="anti_affinity=false" -var="internal_tls=0"

[MichaelThamm]

Can you run just format-terraform-docs to fix the linting issue

[Abuelodelanada]

just format-terraform-docs

just format-terraform-docs
error: Justfile does not contain recipe `format-terraform-docs`

And I get the same error the CI gets:

just lint-terraform-docs
sh: 1: terraform-docs: not found
error: Recipe `lint-terraform-docs` failed on line 32 with exit code 127

Should we install something new?

[MichaelThamm]

Some minor fixes, otherwise looks good!

[MichaelThamm]

just format-terraform-docs

just format-terraform-docs
error: Justfile does not contain recipe `format-terraform-docs`

And I get the same error the CI gets:

just lint-terraform-docs
sh: 1: terraform-docs: not found
error: Recipe `lint-terraform-docs` failed on line 32 with exit code 127

Should we install something new?

I saw you already fixed it. My mistake the recipe was called update-terraform-docs, which I want to rename to format-terraform-docs in the future.

[MichaelThamm]

LGTM