ci: grant ephemeral storage and harden the package install

The backup service test needs 5GiB free on the workspace and the apt mirror
occasionally serves a half-synced index, so both fail the pipeline at random.

- request and limit ephemeral storage on every step
- retry apt-get update and verify fontconfig is loadable before testing
- report workspace free space before the test run
- run the full test filter again

.woodpecker/ci.yaml

@@ -18,9 +18,11 @@ variables:
         requests:
           memory: 2Gi
           cpu: 2
+          ephemeral-storage: 10Gi
         limits:
           memory: 8Gi
           cpu: 4
+          ephemeral-storage: 20Gi
 
 steps:
   - name: restore
@@ -38,13 +40,16 @@ steps:
       - dotnet build Jellyfin.sln -c Release --no-restore
     backend_options: *k8s_resources
 
-  # BackupServiceTests is excluded: BackupService refuses to run with less than
-  # 5GiB free on the backup path, and the pipeline workspace volume is smaller.
   - name: test
     image: *sdk_image
     environment: *dotnet_env
     commands:
       # libSkiaSharp needs fontconfig to load and the SDK image does not ship it.
-      - apt-get update && apt-get install -y --no-install-recommends libfontconfig1
-      - dotnet test Jellyfin.sln -c Release --no-build --verbosity minimal --filter "Category!=RequiresDocker&FullyQualifiedName!~Integration&FullyQualifiedName!~BackupServiceTests"
+      # The mirror occasionally serves a half-synced index, so update is retried.
+      - apt-get -o Acquire::Retries=3 update || apt-get -o Acquire::Retries=3 update
+      - apt-get install -y --no-install-recommends libfontconfig1
+      - ldconfig -p | grep -q libfontconfig
+      # BackupService refuses to run with less than 5GiB free on the backup path.
+      - df -h /woodpecker . && du -sh /woodpecker/nuget /woodpecker/src
+      - dotnet test Jellyfin.sln -c Release --no-build --verbosity minimal --filter "Category!=RequiresDocker&FullyQualifiedName!~Integration"
     backend_options: *k8s_resources