git: openjdk/jdk17u-dev: 8291595: [17u] Delete files missed in backport of 8269039

[Goetz Lindenmaier]

Changeset: c430a945
Author:    Goetz Lindenmaier <goetz at openjdk.org>
Date:      2022-08-03 08:23:10 +0000
URL:       https://git.openjdk.org/jdk17u-dev/commit/c430a9457698fd57a7926e6fab065a639ccfdeb4

8291595: [17u] Delete files missed in backport of 8269039

Reviewed-by: stuefe

- test/jdk/java/security/Security/signedfirst/exp.jar
- test/jdk/java/security/Security/signedfirst/keystore.jks