cli: make crossterm not respect NO_COLOR

The `NO_COLOR` spec says that user-specified config is supposed to
override the `$NO_COLOR` environment variable, and we do correctly use
the `ColorFormatter` when `ui.color= "always"` is set in the user's
config. However, it turns out that `NO_COLOR=1` still resulted in no
color because `crossterm` also respects the variable, so the color
codes the `ColorFormatter` requested had no effect. Since `crossterm`
doesn't know about our user configs, it cannot decide whether to
respect `$NO_COLOR`, so let's tell `crossterm` to always use the
colors we tell it to use.

cli/src/cli_util.rs

@@ -3627,6 +3627,8 @@ impl CliRunner {
             .fold(builder, |builder, config| builder.add_source(config))
             .build()
             .unwrap();
+        // Tell crossterm to ignore NO_COLOR (we check it ourselves)
+        crossterm::style::force_color_output(true);
         let stacked_config = config_from_environment(config);
         let mut ui = Ui::with_config(&stacked_config)
             .expect("default config should be valid, env vars are stringly typed");

cli/tests/test_global_opts.rs

@@ -439,10 +439,9 @@ fn test_color_config() {
     // Test that NO_COLOR does NOT override the request for color in the config file
     test_env.add_env_var("NO_COLOR", "1");
     let stdout = test_env.jj_cmd_success(&repo_path, &["log", "-T", "commit_id"]);
-    // TODO: Should have color
     insta::assert_snapshot!(stdout, @r###"
-    [1m[m@[0m  [m230dd059e1b059aefc0da06a2e5a7dbf22362f22[m
-    [1m[m◆[0m  [m0000000000000000000000000000000000000000[m
+    [1m[38;5;2m@[0m  [38;5;4m230dd059e1b059aefc0da06a2e5a7dbf22362f22[39m
+    [1m[38;5;14m◆[0m  [38;5;4m0000000000000000000000000000000000000000[39m
     "###);
 
     // Test that per-repo config overrides the user config.