gradle-completion: init at 1.3.1 (#42929)

This package adds completion scripts for `gradle` on the `bash` and
`zsh` shells.

The completions can be enabled like this:

```
{ pkgs, ... }:
{
environment.systemPackages = [ pkgs.gradle pkgs.gradle-completion ];
programs.zsh.enable = true;
}
```

The package stores the scripts into the expected directories in
`$out/share` to ensure that the shells can easily find their scripts.

Closes #42799

pkgs/shells/zsh/gradle-completion/default.nix

···
+{ stdenv, fetchFromGitHub }:
+
+stdenv.mkDerivation rec {
+  name = "gradle-completion-${version}";
+  version = "1.3.1";
+
+  src = fetchFromGitHub {
+    owner = "gradle";
+    repo = "gradle-completion";
+    rev = "v${version}";
+    sha256 = "02vv360r78ckwc6r4xbhmy5dxz6l9ya4lq9c62zh12ciq94y9kgx";
+  };
+
+  # we just move two files into $out,
+  # this shouldn't bother Hydra.
+  preferLocalBuild = true;
+
+  dontBuild = true;
+  installPhase = ''
+    runHook preInstall
+
+    mkdir -p $out
+    install -Dm0644 ./_gradle $out/share/zsh/site-functions/_gradle
+    install -Dm0644 ./gradle-completion.bash $out/share/bash-completion/completions/gradle
+
+    runHook postInstall
+  '';
+
+  meta = with stdenv.lib; {
+    description = "Gradle tab completion for bash and zsh";
+    homepage = https://github.com/gradle/gradle-completion;
+    license = licenses.mit;
+    maintainers = with maintainers; [ ma27 ];
+  };
+}

pkgs/top-level/all-packages.nix

···
 
   bash-completion = callPackage ../shells/bash/bash-completion { };
 
+  gradle-completion = callPackage ../shells/zsh/gradle-completion { };
+
   nix-bash-completions = callPackage ../shells/bash/nix-bash-completions { };
 
   dash = callPackage ../shells/dash { };