Remove computed-derivations experimental feature

We don't need it yet.

doc/manual/src/release-notes/rl-next.md

@@ -1,4 +1,3 @@
 # Release X.Y (202?-??-??)
 
-* Add experimental *indexed store derivations* installable syntax, part of the
-  the `computed-derivations` experimental feature.
+* Add *indexed store derivations* installable syntax.

src/libcmd/installables.cc

@@ -814,7 +814,6 @@ std::vector<std::shared_ptr<Installable>> SourceExprCommand::parseInstallables(
                     result.push_back(std::make_shared<InstallableStorePath>(
                         store,
                         DerivedPath::Built::parse(*store, s.substr(0, found), s.substr(found + 1))));
-                    settings.requireExperimentalFeature(Xp::ComputedDerivations);
                     continue;
                 } catch (BadStorePath &) {
                 } catch (...) {

src/libutil/experimental-features.cc

@@ -14,7 +14,6 @@ std::map<ExperimentalFeature, std::string> stringifiedXpFeatures = {
     { Xp::NoUrlLiterals, "no-url-literals" },
     { Xp::FetchClosure, "fetch-closure" },
     { Xp::ReplFlake, "repl-flake" },
-    { Xp::ComputedDerivations, "computed-derivations" },
 };
 
 const std::optional<ExperimentalFeature> parseExperimentalFeature(const std::string_view & name)

src/libutil/experimental-features.hh

@@ -23,7 +23,6 @@ enum struct ExperimentalFeature
     NoUrlLiterals,
     FetchClosure,
     ReplFlake,
-    ComputedDerivations, // RFC 92
 };
 
 /**

src/nix/nix.md

@@ -132,8 +132,6 @@ the Nix store. Here are the recognised types of installables:
 
 * **Indexed store derivations**: `/nix/store/p7gp6lxdg32h4ka1q398wd9r2zkbbz2v-hello-2.10.drv^out`
 
-  *(Experimental, part of by the `computed-derivations` experimental feature.)*
-
   Store derivations can be indexed with a non-empty comma-separated list
   of specific output names, or `*` meaning all ouptuts. This allows
   finer control versus just specifying a derivation (without

tests/build-explicit-output.sh

@@ -2,9 +2,6 @@ source common.sh
 
 set -o pipefail
 
-enableFeatures "computed-derivations"
-restartDaemon
-
 drv=$(nix eval -f multiple-outputs.nix --raw a.drvPath)
 if nix build "$drv^not-an-output" --no-link --json; then
     fail "'not-an-output' should fail to build"