Remove output redirection for previous version in version bump workflow

Author: Vianpyro

.github/workflows/enforce-version-bump.yml

@@ -28,4 +28,4 @@ jobs:
       - name: Get previous version from default branch
         run: |
           PREV_VERSION=$(git show origin/main:Cargo.toml | grep '^version =' | head -n 1 | cut -d '"' -f 2)
-          echo "prev_version=$PREV_VERSION" >> $GITHUB_ENV
+          echo "prev_version=$PREV_VERSION"