Fix Ghostscript tests after default output type changed to 'auto'

- Add --output-type pdfa to tests that exercise Ghostscript-specific
  behavior (test_gs_render_failure, test_ghostscript_pdfa_failure,
  test_ghostscript_mandatory_color_conversion)
- Add Gs106WarningFilter to suppress expected Ghostscript 10.6.x JPEG
  encoding warning in test logs

tests/conftest.py

@@ -3,6 +3,7 @@
 
 from __future__ import annotations
 
+import logging
 import platform
 import sys
 from pathlib import Path
@@ -17,6 +18,27 @@ from ocrmypdf.cli import get_options_and_plugins
 from ocrmypdf.exceptions import ExitCode
 
 
+class Gs106WarningFilter(logging.Filter):
+    """Filter out expected Ghostscript 10.6.x warning from test logs."""
+
+    def filter(self, record: logging.LogRecord) -> bool:
+        # Allow all records except the expected Ghostscript 10.6.x warning
+        if "Ghostscript 10.6.x contains JPEG encoding errors" in record.getMessage():
+            return False
+        return True
+
+
+@pytest.fixture(autouse=True)
+def suppress_gs106_warning():
+    """Suppress the expected Ghostscript 10.6.x JPEG encoding warning in tests."""
+    # Add filter to root logger to suppress expected warnings
+    root_logger = logging.getLogger()
+    warning_filter = Gs106WarningFilter()
+    root_logger.addFilter(warning_filter)
+    yield
+    root_logger.removeFilter(warning_filter)
+
+
 def is_linux():
     return platform.system() == 'Linux'
 

tests/test_ghostscript.py

@@ -84,6 +84,8 @@ def test_gs_render_failure(resources, outpdf, caplog):
     exitcode = run_ocrmypdf_api(
         resources / 'blank.pdf',
         outpdf,
+        '--output-type',
+        'pdfa',  # Required to trigger Ghostscript PDF/A generation
         '--plugin',
         'tests/plugins/tesseract_noop.py',
         '--plugin',
@@ -110,6 +112,8 @@ def test_ghostscript_pdfa_failure(resources, outpdf, caplog):
     exitcode = run_ocrmypdf_api(
         resources / 'francais.pdf',
         outpdf,
+        '--output-type',
+        'pdfa',  # Required to trigger Ghostscript PDF/A generation
         '--plugin',
         'tests/plugins/tesseract_noop.py',
         '--plugin',
@@ -136,6 +140,8 @@ def test_ghostscript_mandatory_color_conversion(resources, outpdf):
         check_ocrmypdf(
             resources / 'jbig2_baddevicen.pdf',
             outpdf,
+            '--output-type',
+            'pdfa',  # Required to trigger Ghostscript PDF/A generation
             '--plugin',
             'tests/plugins/tesseract_noop.py',
         )