security watch: the RUNTIME line names the zstd decoder in words, not the module repr (R-1327)

scripts/test_image_runtime.py

@@ -89,6 +89,11 @@ def zstd_checks():
               found.get("pydist"))
     found, notes = ir.scan_layers(reg, [{"digest": "sha256:zst", "mediaType": ZSTD_MT, "size": 9}],
                                   decoder=(None, "no zstd decoder: test"))
+    ir._ZSTANDARD.clear()
+    how = ir.zstd_decoder_how()
+    check("zstd: the log names the decoder in words", isinstance(how, str) and ("zstandard" in how or "zstd program" in how
+                                                                             or how.startswith("NONE")), how)
+    ir._ZSTANDARD.clear()
     check("zstd: no decoder is a NOTE (NOT CHECKED), never a silent pass", notes and "no zstd decoder" in notes[0]
           and not found, (found, notes))
     mod, _how = ir.zstandard_module()