Replace StringBuffer with StringBuilder in BundleHelper

The local variable `buffer` in `getFilter()` is not shared
across threads, so StringBuilder is the appropriate choice
and avoids unnecessary synchronization overhead.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: laeubi

build/org.eclipse.pde.build/src/org/eclipse/pde/internal/build/BundleHelper.java

@@ -187,7 +187,7 @@ public Filter getFilter(BundleDescription bundleDescription) {
 			if (supplierFilters.size() == 1) {
 				nativeFilter = supplierFilters.get(0).toString();
 			} else if (supplierFilters.size() > 1) {
-				StringBuffer buffer = new StringBuffer("(|"); //$NON-NLS-1$
+				StringBuilder buffer = new StringBuilder("(|"); //$NON-NLS-1$
 				for (Filter filter : supplierFilters) {
 					buffer.append(filter.toString());
 				}