fix: InterpreterMetrics could subtract with overflow

[forsaken628]

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Summary

  11: core::panicking::panic_const::panic_const_sub_overflow
             at /rustc/6b6a867ae9eac4e78d041ac4ee84be1072a48cf7/library/core/src/panicking.rs:182:21
  12: databend_query::interpreters::interpreter_metrics::InterpreterMetrics::record_query_detail
             at /home/coldwater/Projects/github.com/databendlabs/databend/src/query/service/src/interpreters/interpreter_metrics.rs:52:33
  13: databend_query::interpreters::interpreter_metrics::InterpreterMetrics::record_query_finished
             at /home/coldwater/Projects/github.com/databendlabs/databend/src/query/service/src/interpreters/interpreter_metrics.rs:120:9

Tests

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

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 

[what-the-diff]

PR Summary

• Simplified Time Handling
  Removed a piece of code (std::time::UNIX_EPOCH) that was not necessary. This will make the code cleaner and easier to manage.
• Updated Calculation Method
  The process of calculating query_duration_ms has been updated to use duration_since instead of a custom-made function. This can contribute to improved calculation precision and reliability.
• Eliminated Redundant Function
  Quashed the convert_query_timestamp function as it is no longer needed. This helps in making our codebase leaner and more efficient.