Fix icon mapping for phenomena 40

[caiosweet]

Motivation

• The PHENOMENA_ICON mapping contained two adjacent string literals for key 40, which results in accidental concatenation and an invalid icon value.
• Using a single valid Material Design Icon string prevents display and parsing issues in the integration.
• The change aims to ensure consistent icon lookups for the MARI/sea phenomena.

Description

• Updated the PHENOMENA_ICON mapping in custom_components/dpc/api.py to use a single icon for key 40.
• Replaced the concatenated value "mdi:wave" "mdi:sail-boat" with the single icon "mdi:wave" for key 40 in PHENOMENA_ICON.
• Performed a source inspection of the PHENOMENA_ICON dict to ensure there are no other accidental string concatenations.

Testing

• No automated tests were run for this change.

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Codex Task