Fix typo

Signed-off-by: Thomas Leplus <thomasleplus@users.noreply.github.com>

Author: thomasleplus

sigstore-maven-plugin/README.md

@@ -49,7 +49,7 @@ See [GitHub documentation](https://docs.github.com/en/actions/deployment/securit
 Notes:
 
 - GPG: Maven Central publication rules require GPG signing. To avoid GPG signing of `.sigstore.json` signature files, use version 3.2.5 or higher of [maven-gpg-plugin](https://maven.apache.org/plugins/maven-gpg-plugin/).
-- `.md5`/`.sha1`: to avoid unneeded checksum files for `.sigstore.java` files, use Maven 3.9.2 or higher, or create `.mvn/maven.config` file containing `-Daether.checksums.omitChecksumsForExtensions=.asc,.sigstore.java`
+- `.md5`/`.sha1`: to avoid unneeded checksum files for `.sigstore.json` files, use Maven 3.9.2 or higher, or create `.mvn/maven.config` file containing `-Daether.checksums.omitChecksumsForExtensions=.asc,.sigstore.json`
 
 Known limitations: