Fix publish step: remove shell override, add CRLF guard

shell: bash resolves to Cygwin bash on this runner, not git-bash.
The > folded block still needs && echo . to protect the last
argument from \r. Remove the shell override (gh is on PATH in
Cygwin bash) and add the guard. Remove CRLF diagnostic step.

Author: phdye

.github/workflows/release.yml

@@ -35,11 +35,6 @@ jobs:
             ninja
             curl
 
-      # Diagnostic: check whether GitHub Actions adds \r to temp scripts
-      - name: CRLF diagnostic
-        run: >
-          od -c "$0" | tail -3 && echo .
-
       - name: Build environment
         run: >
           echo "GCC=$(g++ -dumpfullversion) CMake=$(cmake --version | head -1) Cygwin=$(uname -r) CWD=$(pwd)"
@@ -157,11 +152,11 @@ jobs:
           && echo .
 
       - name: Publish release
-        shell: bash
         env:
           GH_TOKEN: ${{ github.token }}
         run: >
           gh release create "$GITHUB_REF_NAME"
           --title "Abseil LTS ${GITHUB_REF_NAME%-cygwin} — Cygwin x86_64"
           --notes-file release-notes.md
           "abseil-cpp-$GITHUB_REF_NAME-x86_64.tar.gz" checksums-sha256.txt
+          && echo .