Update master => default

doc/user/clusters/applications.md

@@ -90,7 +90,7 @@ To install applications using GitLab CI/CD:
 1. Optionally, define `.gitlab/managed-apps/<application>/values.yaml` file to
    customize values for the installed application.
 
-A GitLab CI/CD pipeline runs on the `master` branch to install the
+A GitLab CI/CD pipeline runs on the default branch to install the
 applications you have configured. In case of pipeline failure, the
 output of the [Helm Tiller](https://v2.helm.sh/docs/install/#running-tiller-locally) binary
 is saved as a [CI job artifact](../../ci/pipelines/job_artifacts.md).

doc/user/infrastructure/index.md

@@ -38,7 +38,7 @@ This template includes some opinionated decisions, which you can override:
 - Creating [four pipeline stages](https://gitlab.com/gitlab-org/gitlab/-/blob/master/lib/gitlab/ci/templates/Terraform.gitlab-ci.yml):
   `init`, `validate`, `build`, and `deploy`. These stages
   [run the Terraform commands](https://gitlab.com/gitlab-org/gitlab/-/blob/master/lib/gitlab/ci/templates/Terraform/Base.gitlab-ci.yml)
-  `init`, `validate`, `plan`, `plan-json`, and `apply`. The `apply` command only runs on `master`.
+  `init`, `validate`, `plan`, `plan-json`, and `apply`. The `apply` command only runs on the default branch.
 
 This video from January 2021 walks you through all the GitLab Terraform integration features: