Suppressed Ghost logging noise in CI unit tests (#26758)

no issue

Failing unit tests in CI were difficult to reason about because the output was often truncated, hiding the actual failures. Logs from Ghost are also extremely noisy because we're unit testing expected failure cases that were then logging the failures which aren't useful to know about.

- Added `logging__level=fatal` env var to the CI unit test step to suppress Ghost's noisy `info`-level logging output
- The test config had no logging override, so Ghost defaulted to `info` level, flooding CI output and causing truncation that hid real test failures
- Scoped to only the unit test step in CI — no change to local development or other test suites

Author: kevinansfield

.github/workflows/ci.yml

@@ -454,6 +454,7 @@ jobs:
           FORCE_COLOR: 0
           GHOST_UNIT_TEST_VARIANT: ci
           NX_SKIP_LOG_GROUPING: true
+          logging__level: fatal
 
       - uses: actions/upload-artifact@v4
         if: matrix.node == env.NODE_VERSION

ghost/core/test/unit/shared/config/loader.test.js

@@ -29,6 +29,9 @@ describe('Config Loader', function () {
             // we manually call `loadConf` in the tests and we need to ensure that the minimum
             // required config properties are available
             process.env.paths__contentPath = 'content/';
+            // Remove any nconf-style env vars that could interfere with
+            // config hierarchy assertions (e.g. logging__level set by CI)
+            delete process.env.logging__level;
         });
 
         afterEach(function () {