Update mhausenblas/mkdocs-deploy-gh-pages action to v1.26

Change-Id: I467e2dffca2ff15bc77c439e38b8991d99d85221
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 495897b..150e249 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -15,6 +15,6 @@
           fetch-depth: 0
 
       - name: Deploy docs
-        uses: mhausenblas/mkdocs-deploy-gh-pages@786c1c8c1c5ab4ceda14f1579cf417cbd6288825 #1.24
+        uses: mhausenblas/mkdocs-deploy-gh-pages@d77dd03172e96abbcdb081d8c948224762033653 # 1.26
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}