ci: suppress download progress in unmanaged dependency check

[suztomo]

Fixes #2405

[sonarcloud]

Quality Gate passed for 'gapic-generator-java-root'

Kudos, no new issues were introduced!

0 New issues
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarCloud

[sonarcloud]

Quality Gate passed for 'java_showcase_integration_tests'

Kudos, no new issues were introduced!

0 New issues
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarCloud

[suztomo]

"Downstream Check / downstream-compatibility (java-pubsublite)" failed:

Installing this repo's modules to local maven.
Install complete. java-shared-dependencies = 3.23.1-SNAPSHOT
~/work/sdk-platform-java/sdk-platform-java/java-shared-dependencies/target ~/work/sdk-platform-java/sdk-platform-java
Cloning into 'java-pubsublite'...
warning: Could not find remote branch v1.[12](https://github.com/googleapis/sdk-platform-java/actions/runs/7672635937/job/20913560139?pr=2424#step:7:13).21 to clone.
fatal: Remote branch v1.12.21 not found in upstream origin

[suztomo]

It seems v1.12.21 a new release. I'll skip the failure of java-pubsublite.