Description: Add explicit cast to fix ambiguous method call error

Taken from upstream to match expected method call 
https://github.com/biojava/biojava/blob/master/biojava-structure/src/main/java/org/biojava/nbio/structure/chem/ZipChemCompProvider.java

---

Origin: upstream
Forwarded: not-needed
Last-Update: 2022-12-20

--- a/biojava-structure/src/main/java/org/biojava/nbio/structure/io/mmcif/ZipChemCompProvider.java
+++ b/biojava-structure/src/main/java/org/biojava/nbio/structure/io/mmcif/ZipChemCompProvider.java
@@ -293,7 +293,7 @@
 		*/
 
 		// Copy in each file.
-		try (FileSystem zipfs = FileSystems.newFileSystem(zipFile, null)) {
+		try (FileSystem zipfs = FileSystems.newFileSystem(zipFile, (ClassLoader) null)) {
 			Files.createDirectories(pathWithinArchive);
 			for (File f : files) {
 				if (!f.isDirectory() && f.exists()) {