verify-signature cleanup fails with EBUSY when RUNNER_TEMP is on NFS (self-hosted, v6.0.0) #1272

Description:

setup-java's GPG signature verification creates a temporary gpg-agent home directory under RUNNER_TEMP (verify-signature-gpg-home-XXXXXX), then deletes it immediately after verifying. When RUNNER_TEMP is backed by an NFS mount, this cleanup intermittently fails with an EBUSY: resource busy or locked error on the .nfsXXXXXXXX silly-rename placeholder file, causing the step to fail even though signature verification itself succeeded.

Task version:

actions/setup-java@dd06d9cba3e5552c54d9f8ea23572deb30010f7c v6.0.0

Platform:

• Ubuntu
• macOS
• Windows

Runner type:

• Hosted
• Self-hosted

Repro steps:

1. Run a self-hosted runner in Kubernetes container mode (actions-runner-controller / gha-runner-scale-set) with RUNNER_TEMP mapped to a work volume backed by an NFS provisioner.
2. Use actions/setup-java@v6.0.0 with distribution: temurin and java-version: '21' (signature verification enabled).

Expected behavior:

Signature verification succeeds and the temporary GPG home directory is cleaned up without error, regardless of the underlying filesystem backing RUNNER_TEMP.

Actual behavior:

The step fails intermittently with:

Error: Failed to verify signature for Microsoft Build of OpenJDK version 21.0.11. Signature URL: https://aka.ms/download-jdk/microsoft-jdk-21.0.11-linux-x64.tar.gz.sig. Error: File was unable to be removed Error: EBUSY: resource busy or locked, unlink '/__w/_temp/verify-signature-gpg-home-UzV31p/.nfs0058000008bd292700033630'