test: remove legacy/textobjects_spec.lua

It is redundant with `test/old/testdir/test_textobjects.vim`.

test/functional/legacy/textobjects_spec.lua

@@ -1,62 +0,0 @@
-local n = require('test.functional.testnvim')()
-
-local call = n.call
-local clear = n.clear
-local command = n.command
-local expect = n.expect
-local source = n.source
-
-describe('Text object', function()
-  before_each(function()
-    clear()
-    command('set shada=')
-    source([[
-      function SelectionOut(data)
-        new
-        call setline(1, a:data)
-        call setreg('"', '')
-        normal! ggfrmavi)y
-        $put =getreg('\"')
-        call setreg('"', '')
-        normal! `afbmavi)y
-        $put =getreg('\"')
-        call setreg('"', '')
-        normal! `afgmavi)y
-        $put =getreg('\"')
-      endfunction
-      ]])
-  end)
-
-  it('Test for vi) without cpo-M', function()
-    command('set cpo-=M')
-    call('SelectionOut', '(red \\(blue) green)')
-
-    expect([[
-      (red \(blue) green)
-      red \(blue
-      red \(blue
-      ]])
-  end)
-
-  it('Test for vi) with cpo-M #1', function()
-    command('set cpo+=M')
-    call('SelectionOut', '(red \\(blue) green)')
-
-    expect([[
-      (red \(blue) green)
-      red \(blue) green
-      blue
-      red \(blue) green]])
-  end)
-
-  it('Test for vi) with cpo-M #2', function()
-    command('set cpo+=M')
-    call('SelectionOut', '(red (blue\\) green)')
-
-    expect([[
-      (red (blue\) green)
-      red (blue\) green
-      blue\
-      red (blue\) green]])
-  end)
-end)