Remove Ruby 2.7.7 tests from CircleCI (facebook#38611)

Summary:
Pull Request resolved: facebook#38611

For Ruby tests, we are already testing the least recent (2.6.10) and the most recent version (3.2.0).

Testig on 2.7.7 (a minor greater than 2.6.10) was an over-cautious measure we can safely remove now after few months where we saw that no changes broke this specific version of ruby.

## Changelog:
[Internal] - Remove tests on Ruby 2.7.7

Reviewed By: cortinico

Differential Revision: D47715594

fbshipit-source-id: 854b5e0369f390d8801b72f1231fe6ce30069e09

Author: cipolleschi

.circleci/config.yml

@@ -1654,13 +1654,6 @@ workflows:
               architecture: ["NewArch", "OldArch"]
               jsengine: ["Hermes", "JSC"]
               flavor: ["Debug", "Release"]
-      - test_ios_template:
-          requires:
-            - build_npm_package
-          name: "Test Template with Ruby 2.7.7"
-          ruby_version: "2.7.7"
-          architecture: "NewArch"
-          flavor: "Debug"
       - test_ios_template:
           requires:
             - build_npm_package
@@ -1739,12 +1732,6 @@ workflows:
                 jsengine: "JSC"
                 flipper: "WithFlipper"
                 use_frameworks: "DynamicFrameworks"
-      - test_ios_rntester:
-          requires:
-            - build_hermes_macos
-          name: "Test RNTester with Ruby 2.7.7"
-          ruby_version: "2.7.7"
-          architecture: "NewArch"
       - test_ios_rntester:
           requires:
             - build_hermes_macos
@@ -1759,12 +1746,6 @@ workflows:
               architecture: ["NewArch", "OldArch"]
               jsengine: ["Hermes", "JSC"]
               use_frameworks: ["StaticLibraries", "DynamicFrameworks"]
-      - test_ios:
-          name: "Test iOS with Ruby 2.7.7"
-          run_unit_tests: true
-          requires:
-            - build_hermes_macos
-          ruby_version: "2.7.7"
       - test_ios:
           name: "Test iOS with Ruby 3.2.0"
           run_unit_tests: true