feat(snowflake)!: add type annotation for BITNOT

[fivetran-felixhuang]

Platform	Supported	Argument Type	Return Type	Notes
Snowflake	✅ Yes (BITNOT)	Numeric/Binary	INT/BINARY	Returns INT for numeric input, BINARY for binary input
BigQuery	❌ No	N/A	N/A	Uses ~ operator instead for bitwise NOT on INT64/BYTES
Redshift	❌ No	N/A	N/A	Uses ~ operator for bitwise NOT on integers/VARBYTE
PostgreSQL	❌ No	N/A	N/A	Uses ~ operator for bitwise NOT on bit strings/integers
Databricks	❌ No	N/A	N/A	Uses ~ operator for bitwise NOT on numeric expressions
DuckDB	❌ No	N/A	N/A	Uses ~ operator for bitwise NOT on BITSTRING/integers
T-SQL	❌ No	N/A	N/A	Uses ~ operator for bitwise NOT on integers/bit/binary/varbinary