Replace YES_COLOR with CLICOLOR_FORCE

Instead of introducing YES_COLOR, a completely new standard, into the mix
it might make more sense to instead tag along with the CLICOLOR_FORCE env var,
which dates back to at least 2000 with FreeBSD 4.1.1 and which is
supported by tools like CMake.

<https://bixense.com/clicolors/>

test/src/StackTrace.zig

@@ -61,7 +61,7 @@ fn addExpect(
     });
 
     const run = b.addRunArtifact(exe);
-    run.removeEnvironmentVariable("YES_COLOR");
+    run.removeEnvironmentVariable("CLICOLOR_FORCE");
     run.setEnvironmentVariable("NO_COLOR", "1");
     run.expectExitCode(1);
     run.expectStdOutEqual("");