Update GitHub Actions workflows. (#768)

This PR was triggered by @t0yv0 generated by the
update-workflows-ecosystem-providers workflow in the pulumi/ci-mgmt
repo, from commit
[cf7cafe004bfe263736eb8a33fbeead26cc57b58](cf7cafe004).

Co-authored-by: Pulumi Bot <bot@pulumi.com>

.github/workflows/claude.yml

@@ -60,7 +60,7 @@ jobs:
         env:
           MISE_FETCH_REMOTE_VERSIONS_TIMEOUT: 30s
         with:
-          version: 2026.2.10
+          version: 2026.2.15
           github_token: ${{ secrets.GITHUB_TOKEN }}
           # only saving the cache in the prerequisites job
           cache_save: false

.github/workflows/lint.yml

@@ -53,7 +53,7 @@ jobs:
       env:
         MISE_FETCH_REMOTE_VERSIONS_TIMEOUT: 30s
       with:
-        version: 2026.2.10
+        version: 2026.2.15
         github_token: ${{ steps.app-auth.outputs.token }}
         cache_save: false # A different job handles caching our tools.
     - name: prepare workspace