fix(helpers): standardize timeout error message format in composeSignals

• Fix grammatically incorrect timeout message from "timeout {timeout} of ms exceeded"
  to "timeout of {timeout}ms exceeded"
• Aligns composeSignals timeout messaging with xhr and http adapters
• Ensures consistent error message format across all Axios components
• Update corresponding test to expect the corrected message format

Fixes timeout error message inconsistency issue where composeSignals
produced a different format than other adapters.