Stabilize DER system trust export tests across environments (#128)

Relax the system trust export assertions to require at least one generated DER certificate file, since trust store certificate counts vary by OS/JDK.

Co-authored-by: Hendrik Spohr <hendrik@spohr.at>

Author: HendrikSP

src/test/java/nl/altindag/crip/command/export/DerExportCommandShould.java

@@ -153,7 +153,7 @@ void processSystemTrustedCertificates() throws IOException {
                 .collect(Collectors.toList());
 
         assertThat(files)
-                .hasSizeGreaterThan(1)
+                .isNotEmpty()
                 .allMatch(path -> path.toString().endsWith(".crt"));
     }
 

src/test/java/nl/altindag/crip/request/DerExportRequestShould.java

@@ -172,7 +172,7 @@ void processSystemTrustedCertificates() throws IOException {
                 .collect(Collectors.toList());
 
         assertThat(files)
-                .hasSizeGreaterThan(1)
+                .isNotEmpty()
                 .allMatch(path -> path.toString().endsWith(".crt"));
     }