Bump tzinfo-data from 1.2020.5 to 1.2020.6 (#15479)

Bumps [tzinfo-data](https://github.com/tzinfo/tzinfo-data) from 1.2020.5 to 1.2020.6.
- [Release notes](https://github.com/tzinfo/tzinfo-data/releases)
- [Commits](https://github.com/tzinfo/tzinfo-data/compare/v1.2020.5...v1.2020.6)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Gemfile.lock

@@ -639,7 +639,7 @@ GEM
       unf (~> 0.1.0)
     tzinfo (1.2.9)
       thread_safe (~> 0.1)
-    tzinfo-data (1.2020.5)
+    tzinfo-data (1.2020.6)
       tzinfo (>= 1.0.0)
     unf (0.1.4)
       unf_ext