gha(update-docs-webhook): use env variable in shell script

Author: taraspos

.github/workflows/update-docs-webhook.yaml

@@ -25,7 +25,8 @@ jobs:
       - name: Call deployment webhook
         env:
           WEBHOOK_URL: ${{ secrets[matrix.webhooks.url_secret_name] }}
+          HTTP_METHOD: ${{ matrix.webhooks.http_method }}
         run: |
-          if curl -X ${{ matrix.webhooks.http_method }} --silent --fail --show-error "$WEBHOOK_URL" > /dev/null; then
+          if curl -X "$HTTP_METHOD" --silent --fail --show-error "$WEBHOOK_URL" > /dev/null; then
             echo "Triggered successfully"
           fi