Resolving issue with regex for composer environments

[killkelleyr]

Description

Fixes #12580

Checklist

• I have followed Sample Guidelines from AUTHORING_GUIDE.MD
• README is updated to include all relevant information
• Tests pass: nox -s py-3.9 (see Test Environment Setup)
• Lint pass: nox -s lint (see Test Environment Setup)
• These samples need a new API enabled in testing projects to pass (let us know which ones)
• These samples need a new/updated env vars in testing projects set to pass (let us know which ones)
• This sample adds a new sample directory, and I updated the CODEOWNERS file with the codeowners for this sample
• This sample adds a new Product API, and I updated the Blunderbuss issue/PR auto-assigner with the codeowners for this sample
• Please merge this PR for me once it is approved

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[killkelleyr]

Looks like this will require additional changes as it currently produces the following errors since minor and patch are not set.

2024-09-12 14:15:47,029 - Image version: composer-3-airflow-2.9.1-build.6
Traceback (most recent call last):
  File "/home/rkillkelley/composer_dags.py", line 229, in <module>
    main(
  File "/home/rkillkelley/composer_dags.py", line 173, in main
    airflow_version = (int(versions[3]), int(versions[4]), int(versions[5]))
IndexError: tuple index out of range

I will update to ensure minor and patch default to 0

[iennae]

@killkelleyr thanks for contributing this fix. @leahecole can you take a look?