Remove code-view class from diff view (#13011)

code-view class seems unecessary here as everything needed style wise comes from various diff classes. This allows comments and comment editor to be styled properly and fixes linked bug.

Fixes #13010

Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>

templates/repo/diff/box.tmpl

@@ -114,7 +114,7 @@
 					</h4>
 					<div class="diff-file-body ui attached unstackable table segment">
 						{{if ne $file.Type 4}}
-							<div class="file-body file-code code-view has-context-menu code-diff {{if $.IsSplitStyle}}code-diff-split{{else}}code-diff-unified{{end}}">
+							<div class="file-body file-code has-context-menu code-diff {{if $.IsSplitStyle}}code-diff-split{{else}}code-diff-unified{{end}}">
 								<table class="chroma">
 									<tbody>
 										{{if $isImage}}