Deprecate PathResource variant

This commit deprecates the `PathResource` implementation variant in
favor of `FileSystemResource`. This was already pointing to
`FileSystemResource` as of Spring Framework 5.1 and we now consider this
variant as deprecated.

Closes gh-34206

Author: bclozel

spring-core/src/main/java/org/springframework/core/io/PathResource.java

@@ -56,7 +56,9 @@
  * @see java.nio.file.Path
  * @see java.nio.file.Files
  * @see FileSystemResource
+ * @deprecated since 7.0 in favor of {@link FileSystemResource}
  */
+@Deprecated(since = "7.0", forRemoval = true)
 public class PathResource extends AbstractResource implements WritableResource {
 
 	private final Path path;

spring-core/src/test/java/org/springframework/core/io/PathResourceTests.java

@@ -50,6 +50,7 @@
  * @author Juergen Hoeller
  * @author Arjen Poutsma
  */
+@SuppressWarnings("removal")
 class PathResourceTests {
 
 	private static final String TEST_DIR =