feat(icons): add pretix (#1253)

Co-authored-by: Dashboard Icons Manager <193821040+dashboard-icons-manager[bot]@users.noreply.github.com>

tree.json

@@ -1569,6 +1569,7 @@
         "powerpanel.png",
         "premium-mobile.png",
         "premiumize.png",
+        "pretix.png",
         "prime-video-alt-dark.png",
         "prime-video-alt.png",
         "prime-video-light.png",
@@ -3519,6 +3520,7 @@
         "powerbi.svg",
         "powerdns.svg",
         "premiumize.svg",
+        "pretix.svg",
         "prime-video-alt-dark.svg",
         "prime-video-alt.svg",
         "prime-video-light.svg",
@@ -5595,6 +5597,7 @@
         "powerpanel.webp",
         "premium-mobile.webp",
         "premiumize.webp",
+        "pretix.webp",
         "prime-video-alt-dark.webp",
         "prime-video-alt.webp",
         "prime-video-light.webp",