migrate the main rustdoc handlers to axum, drop iron

.cargo/audit.toml

@@ -1,34 +1,16 @@
 [advisories]
 ignore = [
-    "RUSTSEC-2020-0016", # net2 crate has been deprecated; use socket2 instead
-    # https://github.com/rust-lang/docs.rs/issues/760
-
     "RUSTSEC-2020-0036", # failure is officially deprecated/unmaintained
     # https://github.com/rust-lang/docs.rs/issues/1014
 
-    "RUSTSEC-2020-0056", # stdweb is unmaintained
-    # https://github.com/rust-lang/docs.rs/issues/1122
-
     "RUSTSEC-2020-0071", # `time` localtime_r segfault
     # https://github.com/rust-lang/docs.rs/issues/1523
 
     "RUSTSEC-2020-0159", # `chrono` localtime_r segfault
     # https://github.com/rust-lang/docs.rs/issues/1525
 
-    "RUSTSEC-2021-0078", # Lenient hyper header parsing of Content-Length could allow request smuggling
-    # https://github.com/rust-lang/docs.rs/issues/1460
-
-    "RUSTSEC-2021-0079", # Integer overflow in hyper's parsing of the Transfer-Encoding header leads to data loss
-    # https://github.com/rust-lang/docs.rs/issues/1459
-
     "RUSTSEC-2021-0127", # serde_cbor is unmaintained
     # https://github.com/rust-lang/docs.rs/issues/1568
-
-    "RUSTSEC-2021-0144", # traitobject is Unmaintained 
-    # https://github.com/rust-lang/docs.rs/issues/1826
-
-    "RUSTSEC-2019-0039", # typemap is Unmaintained 
-    # https://github.com/rust-lang/docs.rs/issues/1827
 ]
 informational_warnings = ["unmaintained"] # warn for categories of informational advisories
 severity_threshold = "low" # CVSS severity ("none", "low", "medium", "high", "critical")