Electron Releases

Description of Change

Add code to the specs to warn loudly if we try to run specs that require testing builds against release binaries of Electron.

The internalContextBridge test exposure and command-line fuse overrides depend on DCHECK_IS_ON(), as does electron_common_testing. Gate those suites with the existing testing-binding helper while retaining public context-bridge coverage. Allow callers to set ELECTRON_REQUIRE_TESTING_BINDINGS=1 to fail early if expected testing hooks are missing, preventing silent coverage loss in testing jobs. CI wiring for this opt-in flag is separate.

Validation

• Focused Node checks passed for suite selection with/without testing bindings and all six combinations of binding availability and the expectation flag (unset, 0, 1).
• Scoped oxlint, formatting, syntax, and whitespace checks passed.
• The exact patch applies cleanly to 45-x-y, 44-x-y, 43-x-y, and 42-x-y; all have the required helpers.
• Native Electron builds and the full spec suite were not run.

Checklist

• I have built and tested this change
• I have filled out the PR description
• I have reviewed and verified the changes
• npm test passes
• tests are changed or added

Release Notes

Notes: none