Add tfvars filetype

[TylerJang27]

Terraform and tofu can run on .tfvars files (although notably not .tfvars.json). Adds this filetype

Also attempts to fix trivy test failures.

[trunk-io]

⏱️ 3h 44m total CI duration on this PR

Job	Cumulative Duration	Recent Runs
Linter Tests ubuntu-latest	2h 4m	⬜ 🟥 🟥 🟥 🟩 (+1 more)
Linter Tests macOS	1h 5m	🟥 🟥 🟥 🟩 🟩
Windows Linter Tests	19m	🟩 🟥 🟩 🟩 🟩
Trunk Check runner [linux]	6m	🟩 🟩 🟩 🟩 🟩
CodeQL-Build	6m	🟩 🟩 🟩 🟩 🟩
Repo Tests / Plugin Tests	3m	🟩 🟩 🟩 🟩 🟩
Detect changed files	35s	🟩 🟩 🟩 🟩 🟩
Aggregate Test Results	20s	🟥 🟥 🟥 🟥 🟩 (+1 more)

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