fix release workflows

Author: galargh

.github/workflows/pre-release.yml

@@ -1,5 +1,5 @@
 name: Pre Release
-on: 
+on:
   pull_request:
     paths: [CHANGELOG.md]
     branches: [master]
@@ -12,7 +12,7 @@ jobs:
       - run: |
           source .github/scripts/changelog.sh
           git fetch origin --tags
-          if [[ -z "$(git tag -l "v$version")" ]]; then
+          if [[ ! -z "$version" && -z "$(git tag -l "v$version")" ]]; then
             echo "BODY<<EOF" >> $GITHUB_ENV
             echo "$(IFS=$'\n'; echo "${log[*]}")" >> $GITHUB_ENV
             echo "EOF" >> $GITHUB_ENV

.github/workflows/release.yml

@@ -13,7 +13,7 @@ jobs:
       - run: |
           source .github/scripts/changelog.sh
           git fetch origin --tags
-          if [[ -z "$(git tag -l "v$version")" ]]; then
+          if [[ ! -z "$version" && -z "$(git tag -l "v$version")" ]]; then
             git tag "v$major.$minor.$patch"
             git tag "v$major.$minor" --force
             git tag "v$major" --force