Add `trailing_blank_lines_linter()` test for `.qmd` files when no code and no terminal newline present?

[IndrajeetPatil]

For .Rmd, this test produces no error in the document, and so we get only 1 (expected) lint:

tmp4 <- withr::local_tempfile(fileext = ".Rmd")
  cat(
    trim_some(
      '---
      title: "Some file"
      ---
      No code and no terminal newline'
    ),
    file = tmp4
  )
  expect_lint(content = NULL, file = tmp4, list(
    message = msg2,
    line_number = 5L,
    # We can't get 4 here because the line is NA-masked in get_source_expressions(), so no line length info exists.
    column_number = 1L
  ), linter)

For .qmd, the code in question leads to an error (and therefore 2 lints are produced):

tmp6 <- withr::local_tempfile(fileext = ".qmd")
  cat(
    trim_some(
      '---
      title: "Some file"
      ---
      No code and no terminal newline'
    ),
    file = tmp6
  )
  expect_lint(content = NULL, file = tmp6, list(
    message = msg2,
    line_number = 5L,
    # We can't get 4 here because the line is NA-masked in get_source_expressions(), so no line length info exists.
    column_number = 1L
  ), linter)

Do we need to have this test for Quarto documents?

If yes, how should we go about it? Just change the test to expect 2 lints?