ci: release-type should be read by release-please-config

Author: suztomo

.github/release-please.yml

@@ -1,22 +1,15 @@
 handleGHRelease: true
 manifest: true
-releaseType: java-yoshi
 branches:
   - bumpMinorPreMajor: true
     handleGHRelease: true
-    releaseType: java-backport
     branch: 9.0.x-lts
   - bumpMinorPreMajor: true
     handleGHRelease: true
-    releaseType: java-backport
     branch: 8.0.x-lts
   - bumpMinorPreMajor: true
     handleGHRelease: true
-    releaseType: java-backport
     branch: 7.0.x-lts
   - bumpMinorPreMajor: true
     handleGHRelease: true
-    releaseType: java-backport
     branch: 6.0.x-lts
-
-