fix(http): escape / in url parameters (#1264)

Author: shiftinv

changelog/1264.bugfix.rst

@@ -0,0 +1 @@
+Escape forward slashes in HTTP route parameters.

disnake/http.py

@@ -177,7 +177,11 @@ def __init__(self, method: str, path: str, **parameters: Any) -> None:
         url = self.BASE + self.path
         if parameters:
             url = url.format_map(
-                {k: _uriquote(v) if isinstance(v, str) else v for k, v in parameters.items()}
+                {
+                    # `/` should not be considered a safe character by default
+                    k: _uriquote(v, safe="") if isinstance(v, str) else v
+                    for k, v in parameters.items()
+                }
             )
         self.url: str = url