Align `issue-title-buttons` with `list-header` (#35018)

This change concerns the "Edit" and "New Issue" button on top right.
With this change, switching from the issue list into an issue, the "New
Issue" button will no longer "shift" from the postion on the previous
page.

<img width="1299" alt="Screenshot 2025-07-09 at 17 37 31"
src="https://github.com/user-attachments/assets/1ea55d8a-2abd-49b0-951a-ccc6466a74ee"
/>

<img width="1300" alt="Screenshot 2025-07-09 at 17 37 19"
src="https://github.com/user-attachments/assets/05997d9d-25eb-4786-803d-00c575f78bef"
/>

---------

Signed-off-by: silverwind <me@silverwind.io>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

web_src/css/repo.css

@@ -334,7 +334,7 @@ td .commit-summary {
   display: flex;
   gap: 0.5em;
   margin-bottom: 8px;
-  min-height: 40px; /* avoid layout shift on edit */
+  min-height: 36px; /* avoid layout shift on edit */
 }
 
 .repository.view.issue .issue-title h1 {
@@ -342,20 +342,12 @@ td .commit-summary {
   width: 100%;
   font-weight: var(--font-weight-normal);
   font-size: 32px;
-  line-height: 40px;
+  line-height: 36px; /* vertically center single-line text with .issue-title-buttons */
   margin: 0;
   padding-right: 0.25rem;
   overflow-wrap: anywhere;
 }
 
-.repository.view.issue .issue-title#issue-title-display .issue-title-buttons {
-  margin-top: 4px; /* the title's height is 40px, fine tune to align the buttons */
-}
-
-.repository.view.issue .issue-title#issue-title-editor {
-  padding-top: 4px;
-}
-
 @media (max-width: 767.98px) {
   .repository.view.issue .issue-title {
     flex-direction: column;