chore: fix wdc time assertion

[sahiljhawar]

No description provided.

[Copilot]

Pull request overview

This PR updates WDC Dst time-range handling to normalize start_time/end_time to UTC before validating the requested interval, aiming to prevent timezone-related comparison issues.

Changes:

• Normalize start_time and end_time via enforce_utc_timezone() before validation in download_and_process().
• Replace the previous invalid-range ValueError handling in read() with an assertion after timezone normalization.

Comments suppressed due to low confidence (1)

swvo/io/dst/wdc.py:235

• read() previously raised ValueError("start_time must be before end_time") when the time range was invalid (and the tests assert this). This change replaces it with an assert start_time < end_time, which (1) changes the exception type to AssertionError, (2) changes the allowed boundary condition (start==end used to be allowed), and (3) can be skipped entirely when Python is run with optimizations (-O). Keep the timezone normalization (to avoid naive/aware comparison errors), but restore the explicit ValueError check/message.

        start_time = enforce_utc_timezone(start_time)
        end_time = enforce_utc_timezone(end_time)

        assert start_time < end_time, "Start time must be before end time!"

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.