Minor dashboard tweaks, fix flex-list margins (#26829)

Some small dashboard tweaks:

- Remove margin-bottom from divider so first item does not appear to
have un-equal margins
- Restore previous icon color
- Add slight margin-right to icon

Before:
<img width="783" alt="Screenshot 2023-08-31 at 00 10 28"
src="https://github.com/go-gitea/gitea/assets/115237/b75f70d7-8704-4afb-866d-fea0484c52d4">

After:
<img width="783" alt="Screenshot 2023-08-31 at 00 10 08"
src="https://github.com/go-gitea/gitea/assets/115237/50ed0c47-6f7c-449e-a054-13091369d43f">

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

templates/user/dashboard/feeds.tmpl

@@ -116,7 +116,7 @@
 				<div class="flex-item-body">{{TimeSince .GetCreate $.locale}}</div>
 			</div>
 			<div class="flex-item-trailing">
-				{{svg (printf "octicon-%s" (ActionIcon .GetOpType)) 32}}
+				{{svg (printf "octicon-%s" (ActionIcon .GetOpType)) 32 "text grey gt-mr-2"}}
 			</div>
 		</div>
 	{{end}}

templates/user/profile.tmpl

@@ -17,9 +17,7 @@
 						</div>
 					{{end}}
 					{{template "user/heatmap" .}}
-					<div class="feeds">
-						{{template "user/dashboard/feeds" .}}
-					</div>
+					{{template "user/dashboard/feeds" .}}
 				{{else if eq .TabName "stars"}}
 					<div class="stars">
 						{{template "explore/repo_search" .}}

templates/user/settings/keys_gpg.tmpl

@@ -5,7 +5,7 @@
 	</div>
 </h4>
 <div class="ui attached segment">
-	<div class="{{if not .HasGPGError}}gt-hidden{{end}} gt-mb-4" id="add-gpg-key-panel">
+	<div class="{{if not .HasGPGError}}gt-hidden{{end}}" id="add-gpg-key-panel">
 		<form class="ui form{{if .HasGPGError}} error{{end}}" action="{{.Link}}" method="post">
 			{{.CsrfTokenHtml}}
 			<input type="hidden" name="title" value="none">

templates/user/settings/keys_ssh.tmpl

@@ -7,7 +7,7 @@
 	</div>
 </h4>
 <div class="ui attached segment">
-	<div class="{{if not .HasSSHError}}gt-hidden{{end}} gt-mb-4" id="add-ssh-key-panel">
+	<div class="{{if not .HasSSHError}}gt-hidden{{end}}" id="add-ssh-key-panel">
 		<form class="ui form" action="{{.Link}}" method="post">
 			{{.CsrfTokenHtml}}
 			<div class="field {{if .Err_Title}}error{{end}}">