Update rspec-rails to v8 (#111)

Rails 7.2.0 now the minimum required version.

https://github.com/rspec/rspec-rails/blob/v8.0.1/Changelog.md

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

template/{{app_name}}/Gemfile

@@ -84,7 +84,7 @@ group :development, :test do
 
   # Testing framework
   gem "factory_bot_rails"
-  gem "rspec-rails", "~> 6.1.0"
+  gem "rspec-rails", "~> 8.0.0"
 
   # Required by Lookbook
   gem "listen"

template/{{app_name}}/Gemfile.lock

@@ -147,7 +147,7 @@ GEM
       railties (>= 4.1.0)
       responders
       warden (~> 1.2.3)
-    diff-lcs (1.5.1)
+    diff-lcs (1.6.2)
     docile (1.4.1)
     dotenv (3.1.8)
     drb (2.2.3)
@@ -391,23 +391,23 @@ GEM
       rspec-core (~> 3.13.0)
       rspec-expectations (~> 3.13.0)
       rspec-mocks (~> 3.13.0)
-    rspec-core (3.13.2)
+    rspec-core (3.13.5)
       rspec-support (~> 3.13.0)
-    rspec-expectations (3.13.3)
+    rspec-expectations (3.13.5)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.13.0)
-    rspec-mocks (3.13.2)
+    rspec-mocks (3.13.5)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.13.0)
-    rspec-rails (6.1.5)
-      actionpack (>= 6.1)
-      activesupport (>= 6.1)
-      railties (>= 6.1)
+    rspec-rails (8.0.1)
+      actionpack (>= 7.2)
+      activesupport (>= 7.2)
+      railties (>= 7.2)
       rspec-core (~> 3.13)
       rspec-expectations (~> 3.13)
       rspec-mocks (~> 3.13)
       rspec-support (~> 3.13)
-    rspec-support (3.13.2)
+    rspec-support (3.13.4)
     rubocop (1.75.5)
       json (~> 2.3)
       language_server-protocol (~> 3.17.0.2)
@@ -547,7 +547,7 @@ DEPENDENCIES
   rails-erd
   route_translator
   rqrcode
-  rspec-rails (~> 6.1.0)
+  rspec-rails (~> 8.0.0)
   rubocop-rails-omakase
   rubocop-rspec
   selenium-webdriver