fix(ci): bump Go version to 1.26 to resolve stdlib vulnerabilities

CI was using Go 1.24 which has 5 known stdlib vulnerabilities
(crypto/x509, html/template, net/url, os) that cause govulncheck
to fail. Go 1.26 includes all fixes.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

Author: qasim-nylas

.github/workflows/ci.yml

@@ -19,7 +19,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v5
         with:
-          go-version: '1.24'
+          go-version: '1.26'
 
       - name: Download dependencies
         run: go mod download
@@ -48,7 +48,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v5
         with:
-          go-version: '1.24'
+          go-version: '1.26'
 
       - name: Run golangci-lint
         uses: golangci/golangci-lint-action@v7