Bump rails from 7f6714e to f6987c4

Bumps [rails](https://github.com/rails/rails) from `7f6714e` to `f6987c4`.
- [Release notes](https://github.com/rails/rails/releases)
- [Commits](7f6714ed18...f6987c4657)

---
updated-dependencies:
- dependency-name: rails
  dependency-type: direct:production
...

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

Gemfile.lock

@@ -1,6 +1,6 @@
 GIT
   remote: https://github.com/rails/rails.git
-  revision: 7f6714ed182d3d8968f580a60cbaabe7a3b45463
+  revision: f6987c46572666c439a1ad68b3ab5b41645f2bcf
   branch: 7-1-stable
   specs:
     actioncable (7.1.1)
@@ -511,7 +511,7 @@ GEM
       sprockets (>= 3.0.0)
     ssrf_filter (1.1.2)
     stackprof (0.2.25)
-    stringio (3.0.8)
+    stringio (3.0.9)
     telegraf (2.1.1)
       influxdb
     temple (0.10.3)