ci: prepare release please for 1.0 (#995)

- Remove custom config.
- Remove 1.0-dev branch from triggers.

Author: ishymko

.github/workflows/release-please.yml

@@ -2,7 +2,6 @@ on:
   push:
     branches:
       - main
-      - 1.0-dev
 
 permissions:
   contents: write
@@ -17,6 +16,3 @@ jobs:
       - uses: googleapis/release-please-action@16a9c90856f42705d54a6fda1823352bdc62cf38 # v4
         with:
           token: ${{ secrets.A2A_BOT_PAT }}
-          target-branch: ${{ github.ref_name }}
-          config-file: release-please-config.json
-          manifest-file: .release-please-manifest.json