Fix inline snapshot closing """ indentation

[MatthewMckee4]

Summary

• Fixed generate_inline_literal() to indent the closing """ at the content indentation level (base + 4) instead of the call indentation level (base), aligning it with the snapshot content lines.
• Added test_inline_snapshot_multiline_closing_indent integration test to verify correct closing delimiter indentation.
• Updated existing test snapshots affected by the indentation fix.

Test plan

• Unit tests pass: cargo nextest run -p karva_snapshot
• Integration tests pass: cargo nextest run -p karva -E 'test(inline)'
• Full test suite passes: just test (652/652)
• Pre-commit checks pass: uvx prek run -a

[codspeed-hq]

Merging this PR will not alter performance

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

✅ 1 untouched benchmark

---

_{Comparing fix/inline-snapshot-closing-indent (6d691b0) with main (b19404e)}