fix(fastmcp): propagate mimeType in resource template list (#1186)

Co-authored-by: Felix Weinberger <3823880+felixweinberger@users.noreply.github.com>

src/mcp/server/fastmcp/server.py

@@ -320,6 +320,7 @@ class FastMCP(Generic[LifespanResultT]):
                 name=template.name,
                 title=template.title,
                 description=template.description,
+                mimeType=template.mime_type,
             )
             for template in templates
         ]