Update English README only if it exists

Author: m-aciek

.github/workflows/update-lint-and-build.yml

@@ -41,6 +41,7 @@ jobs:
           TX_TOKEN: ${{ secrets.TX_TOKEN }}
       # Process README.en.md
       - run: python -Werror -m cogapp -rP README.en.md
+        if: ${{ hashFiles('README.en.md') != '' }}
         env:
           TX_TOKEN: ${{ secrets.TX_TOKEN }}
       - run: git config --local user.email [email protected]