STF-322: Restore interrupt flag in InterruptedException rewrap path

The existing catch (InterruptedException) block in responseFor() rewraps
into GeoIp2Exception without restoring the thread's interrupt status,
silently swallowing the cancellation signal. Per Java's interruption
protocol, code that catches InterruptedException without rethrowing it
should re-set the flag so callers up the stack can observe the
cancellation.

This is an independent bug fix bundled into the STF-322 retry work because
the retry feature exposes the path more often. Per project commit hygiene
it lands as a separate commit so it can be cherry-picked or reverted on
its own.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: oschwald

src/main/java/com/maxmind/geoip2/WebServiceClient.java

@@ -418,6 +418,7 @@ private <T> T responseFor(String path, InetAddress ipAddress, Class<T> cls)
                 response.body().close();
             }
         } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
             throw new GeoIp2Exception("Interrupted sending request", e);
         }
     }