add optional hook before building klotho

[ghost]

Standard checks

• Unit tests: n/a
• Docs: n/a
• Backwards compatibility: no issues

[ghost]

Proof of it working with no hook provided: https://github.com/klothoplatform/klotho/actions/runs/4016914665/jobs/6900580016

[github-actions]

Package	Line Rate	Health
github.com/klothoplatform/klotho/pkg/analytics	2%	❌
github.com/klothoplatform/klotho/pkg/annotation	23%	❌
github.com/klothoplatform/klotho/pkg/cli	4%	❌
github.com/klothoplatform/klotho/pkg/core	20%	❌
github.com/klothoplatform/klotho/pkg/env_var	82%	✔
github.com/klothoplatform/klotho/pkg/exec_unit	54%	➖
github.com/klothoplatform/klotho/pkg/infra/kubernetes	59%	➖
github.com/klothoplatform/klotho/pkg/infra/kubernetes/helm	39%	❌
github.com/klothoplatform/klotho/pkg/input	63%	➖
github.com/klothoplatform/klotho/pkg/lang	37%	❌
github.com/klothoplatform/klotho/pkg/lang/dockerfile	0%	❌
github.com/klothoplatform/klotho/pkg/lang/golang	9%	❌
github.com/klothoplatform/klotho/pkg/lang/javascript	47%	❌
github.com/klothoplatform/klotho/pkg/lang/python	60%	➖
github.com/klothoplatform/klotho/pkg/lang/yaml	0%	❌
github.com/klothoplatform/klotho/pkg/logging	7%	❌
github.com/klothoplatform/klotho/pkg/multierr	95%	✔
github.com/klothoplatform/klotho/pkg/provider/aws	59%	➖
github.com/klothoplatform/klotho/pkg/runtime	75%	✔
github.com/klothoplatform/klotho/pkg/static_unit	32%	❌
github.com/klothoplatform/klotho/pkg/validation	73%	➖
github.com/klothoplatform/klotho/pkg/yaml_util	79%	✔
Summary	40% (3722 / 9373)	❌