Fix google_credentials

[aaylward]

Related to #44

When config.js tried to write GCP credentials to a temporary directory in GHA, I see the following error:

Error: EACCES: permission denied, mkdtemp '/tmpXXXXXX'
    at Object.mkdtempSync (node:fs:2971:18)
    at Object.700 (/home/runner/work/_actions/bazel-contrib/setup-bazel/0.9.0/dist/config.js:67:1)
    at __nccwpck_require__ (/home/runner/work/_actions/bazel-contrib/setup-bazel/0.9.0/dist/webpack/bootstrap:21:1)
    at /home/runner/work/_actions/bazel-contrib/setup-bazel/0.9.0/dist/index.js:8:1
    at Object.<anonymous> (/home/runner/work/_actions/bazel-contrib/setup-bazel/0.9.0/dist/main/index.js:97137:12)
    at Module._compile (node:internal/modules/cjs/loader:1358:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1416:10)
    at Module.load (node:internal/modules/cjs/loader:1208:32)
    at Function.Module._load (node:internal/modules/cjs/loader:1024:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:174:12)

Per actions/toolkit#518 runners have a temporary directory provisioned for them accessible from process.env.RUNNER_TEMP. Runners have permission to create new temp directories inside RUNNER_TEMP.

Tested at https://github.com/muchq/MoonBase/actions/runs/11601472019/job/32304285543