simplify loops to find exec units

[ghost]

Rather than looping over result.Resources(), use GetResourcesOfType[ExecutionUnit]. This is a newer form of the original loop, so this is just some cleanup.

I found these while going through our plugins to catalogue what uses what.

Standard checks

• Unit tests: none changed
• Docs: n/a
• Backwards compatibility: should be fine

[gordon-klotho]

Nice

[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	21%	❌
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	38%	❌
github.com/klothoplatform/klotho/pkg/lang/dockerfile	0%	❌
github.com/klothoplatform/klotho/pkg/lang/golang	19%	❌
github.com/klothoplatform/klotho/pkg/lang/javascript	47%	❌
github.com/klothoplatform/klotho/pkg/lang/python	61%	➖
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	33%	❌
github.com/klothoplatform/klotho/pkg/validation	73%	➖
github.com/klothoplatform/klotho/pkg/yaml_util	79%	✔
Summary	40% (3793 / 9417)	❌