fix: sort tags

tags should be sorted before planning. tags_list is an ordered list. This causes an issue when planning as terraform always tries to apply the new tag list, even though they're alike, just in different order

resource "gitlab_runner" "this" {
  ...
  tags_list = ["c", "b", "a"]
}

will always plan and apply changes

# gitlab_runner.this will be updated in-place
~ resource "gitlab_runner" "this" {
      id                   = "123"
    ~ tag_list             = [
        - "a",
        + "c",
          "b",
        - "c",
        + "a",
      ]
  }