Bump hiredis from 0.6.1 to 0.6.3 (#9240)

Bumps [hiredis](https://github.com/redis/hiredis-rb) from 0.6.1 to 0.6.3.
- [Release notes](https://github.com/redis/hiredis-rb/releases)
- [Changelog](https://github.com/redis/hiredis-rb/blob/master/CHANGELOG.md)
- [Commits](https://github.com/redis/hiredis-rb/compare/v0.6.1...v0.6.3)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Gemfile.lock

@@ -254,7 +254,7 @@ GEM
     hashie (3.5.7)
     heapy (0.1.4)
     highline (2.0.0)
-    hiredis (0.6.1)
+    hiredis (0.6.3)
     hitimes (1.3.0)
     hkdf (0.3.0)
     htmlentities (4.3.4)