Set RELEASE_VERSION for main in checksums job

Signed-off-by: Ryan Levick <ryan.levick@fermyon.com>

Author: rylev

.github/workflows/release.yaml

@@ -205,9 +205,15 @@ jobs:
     steps:
 
       - name: set the release version (tag)
+        if: startsWith(github.ref, 'refs/tags/v')
         shell: bash
         run: echo "RELEASE_VERSION=${GITHUB_REF/refs\/tags\//}" >> $GITHUB_ENV
 
+      - name: set the release version (main)
+        if: github.ref == 'refs/heads/main'
+        shell: bash
+        run: echo "RELEASE_VERSION=canary" >> $GITHUB_ENV
+
       - name: download release assets
         uses: actions/download-artifact@v3