Update medical claim sample seed file

[sarah-tuva]

Describe your changes

Updated medical claim sample seed file with new total_cost_amount field following the Tuva Claims Data Model changes.

How has this been tested?

Ran dbt build in Snowflake.

Reviewer focus

n/a

Checklist before requesting a review

• [ ] I have recorded a Loom performing a self-review of my code
• [ ] My code follows style guidelines
• [x] I have tested my code by running dbt build in Snowflake
• [ ] I have tested my code by running dbt build in Redshift
• [ ] I have tested my code by running dbt build in BigQuery
• [ ] (New models only) I have implemented generic dbt tests to validate primary keys/uniqueness in my model
• [ ] I have updated dbt docs by running dbt docs generate and copying the appropriate files to the docs/ path
• [x] I have added at least one Github label to this PR

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