Add disable-model-invocation to skills we only ever expect to invoke manually. (#54694)

.github/skills/analyze-ci-failures/SKILL.md

@@ -14,6 +14,7 @@ description: >
   When requested analysis lacks local evidence, run fetch-vcpkg-ci-logs as the acquisition stage first.
 
   **ANALYSIS SKILL** USES: locally collected CI logs, vcpkg baselines, Azure DevOps metadata.
+disable-model-invocation: true
 ---
 
 # vcpkg CI Failures Analyzer

.github/skills/review-vcpkg-pr/SKILL.md

@@ -1,6 +1,7 @@
 ---
 name: review-vcpkg-pr
 description: Review a microsoft/vcpkg pull request end-to-end.
+disable-model-invocation: true
 ---
 
 ## Inputs

.github/skills/review-vcpkg-prs-today/SKILL.md

@@ -1,6 +1,7 @@
 ---
 name: review-vcpkg-prs-today
 description: Review open non-draft microsoft/vcpkg pull requests updated in the last 30 days. Use when asked for batch triage, per-PR review reports, an index grouped by verdict, or grouping competing PRs that modify the same port.
+disable-model-invocation: true
 ---
 
 ## Inputs