release.version multi-select filter returns 400 due to unsupported IN operator in semver pipeline

[sentry-junior]

Selecting multiple values for release.version in a dashboard widget filter produces a 400 "Invalid Query" response. A single release.version value works fine.

Root cause

release.version uses the semver filter pipeline, which only supports operators that map to Django/semver semantics (=, !=, >=, etc.). When multiple values are selected, the query builder emits an IN operator, which is not handled by the semver converter:

# src/sentry/search/events/filter.py (~line 467)
try:
    operator = OPERATOR_TO_DJANGO[operator]
except KeyError:
    raise InvalidSearchQuery("Invalid operation 'IN' for semantic version filter.")

By contrast, the plain release filter field supports multi-value selection via release_filter_converter in src/sentry/search/events/datasets/filter_aliases.py, which explicitly maps = → IN and resolves release strings before passing to the default filter converter.

Reproduction

1. Open a dashboard widget with a release.version filter.
2. Select two or more release versions from the dropdown (operator: "is").
3. The widget query returns HTTP 400 "Invalid Query".

Workaround

• Use the release filter field (full release string) instead of release.version when multiple versions need to be selected simultaneously.
• If release.version is required, restrict to one value at a time.

Fix direction

Extend the release.version filter handler so that multi-value inputs are resolved to their corresponding release strings and forwarded as an IN clause (similar to how release_filter_converter works), rather than passing IN directly through the semver operator converter.

Action taken on behalf of Chris Stavitsky.

[linear-code]

ENG-7356

[cstavitsky]

For context: these conditions create the bug

If I substitute release instead of release.version, the widget works.