Sqlite3 semconv optin tests (#4836)

* opentelemetry-instrumentation-sqlite3: add semconv stability opt-in test coverage

Cover database,http and database/dup,http/dup opt-in modes, verifying
stable-only and dual-emission span attributes, mirroring the pattern
from #4810. sqlite3 captures no connection attributes, so only
db.system.name/db.query.text (and their legacy counterparts in dup
mode) are asserted.

* Add changelog fragment for semconv opt-in mode tests

* opentelemetry-instrumentation-sqlite3: add default semconv mode test

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Co-authored-by: Emídio <9735060+emdneto@users.noreply.github.com>