Left align the input labels for the link account page (#29255)

In a previous [PR](https://github.com/go-gitea/gitea/pull/28753) we
moved the labels to be above the inputs. The PR ensures that the
alignment is also on both tabs of the link account page
(`/user/link_account`).

Before
<img width="1094" alt="before"
src="https://github.com/go-gitea/gitea/assets/6152817/ac1e86bd-c4d6-4e45-87d1-87bb8a736149">

After
<img width="1094" alt="after"
src="https://github.com/go-gitea/gitea/assets/6152817/1b5fc109-f4d2-43ee-b924-0a9e53a0e391">

---------

Co-authored-by: rafh <rafaelheard@gmail.com>

web_src/css/form.css

@@ -242,7 +242,6 @@ textarea:focus,
 .user.activate form,
 .user.forgot.password form,
 .user.reset.password form,
-.user.link-account form,
 .user.signup form {
   margin: auto;
   width: 700px !important;
@@ -277,7 +276,6 @@ textarea:focus,
   .user.activate form .inline.field > label,
   .user.forgot.password form .inline.field > label,
   .user.reset.password form .inline.field > label,
-  .user.link-account form .inline.field > label,
   .user.signup form .inline.field > label {
     text-align: right;
     width: 250px !important;