Slightly reduce exclamation icon size (#20753)

It seemed a tad to big compared to other icons. Shrink it slightly.

Co-authored-by: Lauris BH <lauris@nix.lv>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>

public/img/svg/gitea-exclamation.svg

@@ -1 +1 @@
-<svg viewBox="0 0 24 24" class="svg gitea-exclamation" width="16" height="16" aria-hidden="true"><path d="M12 15.99a2 2 0 0 0 2-2V2.03a2 2 0 0 0-4 0v11.96a2 2 0 0 0 2 2zm0 7.98a2.5 2.5 0 1 0-2.5-2.5 2.5 2.5 0 0 0 2.5 2.5z"/></svg>
+<svg viewBox="-1 -1 26 26" class="svg gitea-exclamation" width="16" height="16" aria-hidden="true"><path d="M12 15.99a2 2 0 0 0 2-2V2.03a2 2 0 0 0-4 0v11.96a2 2 0 0 0 2 2zm0 7.98a2.5 2.5 0 1 0-2.5-2.5 2.5 2.5 0 0 0 2.5 2.5z"/></svg>

web_src/svg/gitea-exclamation.svg

@@ -1 +1 @@
-<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24"><path d="M12 15.99a2 2 0 0 0 2-2V2.03a2 2 0 0 0-4 0v11.96a2 2 0 0 0 2 2zm0 7.98a2.5 2.5 0 1 0-2.5-2.5 2.5 2.5 0 0 0 2.5 2.5z"/></svg>
+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="-1 -1 26 26"><path d="M12 15.99a2 2 0 0 0 2-2V2.03a2 2 0 0 0-4 0v11.96a2 2 0 0 0 2 2zm0 7.98a2.5 2.5 0 1 0-2.5-2.5 2.5 2.5 0 0 0 2.5 2.5z"/></svg>