libutil: remove the no-url-literals experimental feature

URL literals were deprecated in 278fddc317,
effectively stabilizing the experimental feature. Enabling it has no effect any
more. Remove it.

Change-Id: I8fbca03b1a2be6a8cddfce644043ac0a6a6a6964

lix/libutil/experimental-features/no-url-literals.md

@@ -1,39 +0,0 @@
----
-name: no-url-literals
-internalName: NoUrlLiterals
----
-Disallow unquoted URLs as part of the Nix language syntax. The Nix
-language allows for URL literals, like so:
-
-```
-$ nix repl
-Welcome to Nix 2.15.0. Type :? for help.
-
-nix-repl> http://foo
-"http://foo"
-```
-
-But enabling this experimental feature will cause the Nix parser to
-throw an error when encountering a URL literal:
-
-```
-$ nix repl --extra-experimental-features 'no-url-literals'
-Welcome to Nix 2.15.0. Type :? for help.
-
-nix-repl> http://foo
-error: URL literals are disabled
-
-at «string»:1:1:
-
-1| http://foo
- | ^
-
-```
-
-While this is currently an experimental feature, unquoted URLs are
-being deprecated and their usage is discouraged.
-
-The reason is that, as opposed to path literals, URLs have no
-special properties that distinguish them from regular strings, URLs
-containing parameters have to be quoted anyway, and unquoted URLs
-may confuse external tooling.

lix/libutil/meson.build

@@ -163,7 +163,6 @@ experimental_feature_definitions = files(
   'experimental-features/flakes.md',
   'experimental-features/lix-custom-sub-commands.md',
   'experimental-features/nix-command.md',
-  'experimental-features/no-url-literals.md',
   'experimental-features/pipe-operator.md',
   'experimental-features/read-only-local-store.md',
   'experimental-features/repl-automation.md',