Bump go (#1041)

<!-- Provide a brief summary of your changes -->
Fixes:
https://github.com/modelcontextprotocol/registry/actions/runs/22784360696/job/66097670402
## Motivation and Context
<!-- Why is this change needed? What problem does it solve? -->

## How Has This Been Tested?
<!-- Have you tested this in a real application? Which scenarios were
tested? -->

## Breaking Changes
<!-- Will users need to update their code or configurations? -->

## Types of changes
<!-- What types of changes does your code introduce? Put an `x` in all
the boxes that apply: -->
- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update

## Checklist
<!-- Go over all the following points, and put an `x` in all the boxes
that apply. -->
- [ ] I have read the [MCP
Documentation](https://modelcontextprotocol.io)
- [ ] My code follows the repository's style guidelines
- [ ] New and existing tests pass locally
- [ ] I have added appropriate error handling
- [ ] I have added or updated documentation as needed

## Additional context
<!-- Add any other context, implementation notes, or design decisions
-->

---------

Signed-off-by: Radoslav Dimitrov <radoslav@stacklok.com>

.github/workflows/ci.yml

@@ -38,8 +38,9 @@ jobs:
     - name: Run govulncheck
       uses: golang/govulncheck-action@v1
       with:
-        go-version-input: ''
-        go-version-file: go.mod
+        # Use Go 1.26.1 to pick up crypto/x509 vulnerability fixes (GO-2026-4600, GO-2026-4599).
+        # go.mod stays at go 1.25.8 for golangci-lint compatibility until it supports Go 1.26.
+        go-version-input: '1.26.1'
         go-package: ./...
         repo-checkout: false