[adrastogi]

Description

Reconfigures the misspell step of the Optional Lint job in .github/workflows/lint.yml:

• Run the optional-lint job only on pull_request (both of its steps use reviewdog's github-pr-check reporter).
• Drop locale: "US" so valid UK spellings (behaviour, cancelled, the public CANCELLED status code, ...) are accepted.
• Ignore false positives (case-insensitive): nto (NTO = NodesToOptimize alias in optimizer code), spectre (the CPU vulnerability, flagged as a UK spelling of "specter"), interm (s390x MLAS variable).
• Exclude .git, package-lock.json, and the vendored/minified DocFX templates under csharp/ApiDocs/_exported_templates.
• Switch to filter_mode: added + fail_level: any so new typos fail the PR check instead of accumulating on main.

The remaining 37 genuine typos on main are fixed in a companion PR.

Validation (local, using the checksum-verified golangci/misspell v0.8.0 Windows binary, the version pinned in the action's Docker image, over git ls-files):

• Current config (-locale US): 280 findings, matching CI's 278 (reported too many annotation (N=278)).
• New config (-i nto,spectre,interm, same excludes): 37 findings, all genuine typos (fixed in the companion PR).
• Exclude patterns checked with find . -not -path ... (Git Bash): no .git/, package-lock.json, or docfx.vendor.js paths remain.
• python -c "import yaml; yaml.safe_load(open('.github/workflows/lint.yml'))": passed.

Motivation and Context

Every push to main produces a Lint failure email (300+ consecutive failed runs, e.g. https://github.com/microsoft/onnxruntime/actions/runs/41116362817). On push there is no PR diff, so filter_mode: diff_context filters nothing and misspell reports every existing finding repo-wide. reviewdog then falls back to log annotations, and its GitHubActionLogWriter.Flush returns an error whenever more than 9 results are reported (reviewdog: Too many results (annotations) in diff / reported too many annotation (N=278)), regardless of fail_level. The Optional Lint C++ job hits the same error but is masked by continue-on-error: true.

[Copilot]

🟢 Approval recommended

No active review issues were identified for the targeted pull-request spell-check changes.

No open issues 🎉

What changed in this PR

Updates Optional Lint so misspell checks focus on newly added PR content and fail on new typos without reporting known false positives.

Changes:

• Runs Optional Lint only for pull requests.
• Accepts US and UK spellings, ignores three known false positives, and excludes Git metadata, lockfiles, and vendored DocFX templates.
• Uses added-line filtering and fails the misspell step on any reported finding.

File	Description
.github/​workflows/​lint.yml	Restricts Optional Lint to PRs and configures targeted, blocking spell checks.

_{Review effort: Balanced}