chore(deps): don't use rustic_core webdav feature (#1367)

..no longer needed after #1363

Co-authored-by: simonsan <14062932+simonsan@users.noreply.github.com>

Cargo.lock

@@ -4275,7 +4275,6 @@ dependencies = [
  "clap",
  "conflate",
  "crossbeam-channel",
- "dav-server",
  "derive_more",
  "derive_setters",
  "dirs",
@@ -4286,7 +4285,6 @@ dependencies = [
  "enum-map-derive",
  "enumset",
  "filetime",
- "futures",
  "gethostname",
  "hex",
  "humantime",

Cargo.toml

@@ -32,7 +32,6 @@ webdav = [
   "dep:dav-server",
   "dep:warp",
   "dep:tokio",
-  "rustic_core/webdav",
   "dep:bytes",
   "dep:futures",
 ]