Update version references to v0.1.5b

Author: github-actions[bot]

.github/workflows/example.yml

@@ -18,7 +18,7 @@ jobs:
       issues: write
     steps:
       - name: Improve Issue Titles
-        uses: horw/issue-title-ai@v0.1.4b
+        uses: horw/issue-title-ai@v0.1.5b
         with:
           github-token: ${{ github.token }}
           # gemini-api-key: ${{ secrets.GEMINI_API_KEY }}

README.md

@@ -59,7 +59,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Improve Issue Titles
-        uses: horw/issue-title-ai@v0.1.4b
+        uses: horw/issue-title-ai@v0.1.5b
         with:
           github-token: ${{ secrets.GITHUB_TOKEN }}
           # Choose one of these API keys based on your preference