fix(query): handle malformed UDF script metadata

[KKould]

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Summary

• Return a semantic error when UDF script metadata contains malformed TOML instead of panicking during dependency extraction.
• Apply the same error propagation to script UDF runtime dependency extraction so malformed # /// script metadata is handled consistently.
• Add regression coverage for malformed dependencies = [ metadata.

Tests

• Unit Test
• Logic Test
• Benchmark Test
• No Test - Explain why

cargo fmt --package databend-common-sql --package databend-query-script-udf-support
cargo test -p databend-common-sql test_extract_script_metadata_deps_returns_error_for_malformed_toml
cargo test -p databend-query-script-udf-support --features script-udf test_extract_deps_returns_error_for_malformed_toml
git diff --check

Type of change

• Bug Fix (non-breaking change which fixes an issue)
• New Feature (non-breaking change which adds functionality)
• Breaking Change (fix or feature that could cause existing functionality not to work as expected)
• Documentation Update
• Refactoring
• Performance Improvement
• Other (please describe):

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This change is