chore: update librarian version to v0.44.0 (#14394)

Update librarian version to v0.44.0.

## Debug Info
### System Details
- JDK version: javac 17.0.20.1
- Maven version: �[1mApache Maven 3.9.12�[m
- OS: Linux 6.18.14-1rodete4-amd64 x86_64
- Librarian version: v0.44.0

### Commands Executed
- `go run github.com/googleapis/librarian/cmd/librarian@latest update
version`
- `go run github.com/googleapis/librarian/cmd/librarian@v0.44.0 tidy`
- `go run github.com/googleapis/librarian/cmd/librarian@v0.44.0 install`
- `go run github.com/googleapis/librarian/cmd/librarian@v0.44.0 generate
--all`
- `git add .`
- `git commit -m "chore: update librarian version to v0.44.0"`

Author: zhumin8

librarian.yaml

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 language: java
-version: v0.42.1-0.20260910200322-b1deabc79631
+version: v0.44.0
 repo: googleapis/google-cloud-java
 sources:
   googleapis: