fix(ui): use discussions icon in issue list entries (#7099)

So it is consistent with the icon used in the tab with comments.

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/7099
Reviewed-by: Gusted <gusted@noreply.codeberg.org>
Co-authored-by: 0ko <0ko@noreply.codeberg.org>
Co-committed-by: 0ko <0ko@noreply.codeberg.org>

templates/shared/issuelist.tmpl

@@ -45,7 +45,7 @@
 						{{if .NumComments}}
 						<div class="text grey">
 							<a class="tw-no-underline muted flex-text-block" href="{{if .Link}}{{.Link}}{{else}}{{$.Link}}/{{.Index}}{{end}}">
-								{{svg "octicon-comment" 16}}{{.NumComments}}
+								{{svg "octicon-comment-discussion" 16}}{{.NumComments}}
 							</a>
 						</div>
 						{{end}}