feat: add build job

- add build job that runs `make plan`
- enable provider caching

Makefile

@@ -5,12 +5,13 @@ ENV_DIR = environments/$(ENVIRONMENT)
 .PHONY: clean init plan apply venv hiera output
 
 define vault_env
-	@export VAULT_ADDR="https://vault.service.consul:8200" && \
+	export VAULT_ADDR="https://vault.service.consul:8200" && \
 	export VAULT_TOKEN=$$(vault write -field=token auth/approle/login role_id=$$VAULT_ROLEID) && \
 	export PUPPET_CERT_CA=$$(vault kv get -field=public_key kv/service/puppet/certificates/ca) && \
 	export PUPPET_CERT_PUB=$$(vault kv get -field=public_key kv/service/puppet/certificates/terraform) && \
 	export PUPPET_CERT_PRIV=$$(vault kv get -field=private_key kv/service/puppet/certificates/terraform) && \
 	export TG_QUEUE_EXCLUDE_DIR="templates/base" && \
+	export TG_PROVIDER_CACHE=1 && \
 	export $$(vault read -format=json kv/data/service/terraform/incus | jq -r '.data.data | to_entries[] | "\(.key)=\(.value)"')
 endef
 
@@ -22,7 +23,7 @@ clean:
 	@rm -rf .venv
 
 init:
-	@$(call vault_env) && \
+	$(call vault_env) && \
 	terragrunt run --all --non-interactive init -- -upgrade
 
 plan: init