fix(parser): drop uncredited unknown condition ticks

[Roddygithub]

Summary

• drop EVTC2025 source-less UNKNOWN-iff condition ticks before master attribution
• add a parser regression test for the uncredited master condition tick case
• improves EI parity from 196 to 190 differences on the corpus

Verification

• uv run pytest libs/gw2_evtc_parser/tests/test_parser_emit_buff.py::test_parse_events_2025_drops_unknown_iff_uncredited_master_condition_damage libs/gw2_evtc_parser/tests/test_parser_emit_buff.py::test_parse_events_2025_keeps_unknown_iff_damage -q
• uv run ruff check --output-format=concise libs/gw2_evtc_parser/src/gw2_evtc_parser/parser.py libs/gw2_evtc_parser/tests/test_parser_emit_buff.py
• uv run ruff format --check libs/gw2_evtc_parser/src/gw2_evtc_parser/parser.py libs/gw2_evtc_parser/tests/test_parser_emit_buff.py
• uv run python scripts/ei-parity/ei_diff.py --json /tmp/opencode/ei_after_condition_filter.json