Fix dbt delete without project path

[jeremybeard]

Description

This change fixes a bug in astro dbt delete where if the project path is not specified then it does not correctly look at the current working directory for the dbt project.

🧪 Functional Testing

• Unit tests
• Manually tested

📋 Checklist

• [x] Rebased from the main (or release if patching) branch (before testing)
• [x] Ran make test before taking out of draft
• [x] Ran make lint before taking out of draft
• [x] Added/updated applicable tests
• [x] Tested against Astro-API (if necessary).
• [ ] Tested against Houston-API and Astronomer (if necessary).
• [ ] Communicated to/tagged owners of respective clients potentially impacted by these changes.
• [ ] Updated any related documentation

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 86.33%. Comparing base (a8e81d7) to head (d3322ab). Report is 1 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1678 +/- ## ========================================== + Coverage 86.31% 86.33% +0.01% ========================================== Files 116 116 Lines 17052 17055 +3 ========================================== + Hits 14719 14724 +5 + Misses 1403 1402 -1 + Partials 930 929 -1 ```

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