Because Spring Framework already has a security policy, this shows up in
the issue template automatically. This commit removes the extra external
link and updates the original security policy.
See gh-33711
This commit adds a link to the now published information on spring.io
about the GPG key used to sign the Spring artifacts published on Maven
Central.
Closes gh-23434
Rossen Stoyanchev
Brian Clozel
Brian Clozel
Sam Brannen