print various environments variable from CI

CI is currently failing with the following error:
```
go: errors parsing go.mod:
/home/runner/work/world/world/go.mod:3: invalid go version '1.21.4': must match format 1.23
```

From [1]:
> Before Go 1.21, the initial release of a Go toolchain was version 1.N, not 1.N.0

which makes me think that I'm CI is running with a version of go older
than 1.21, while I specify 1.21 in my nix config. If that's the case,
something is not correct in the CI environment and I should fix it.

Hopefully the script will give me the information I need to debug this.

[1] https://go.dev/doc/toolchain#version

1 files changed, 25 insertions, 0 deletions

diff --git a/ci/build-environment.py b/ci/build-environment.py
new file mode 100755
index 0000000..64a827a
--- /dev/null
+++ b/ci/build-environment.py
@@ -0,0 +1,25 @@
+#!/usr/bin/env python3
+
+from shutil import which
+import subprocess
+
+
+def go_version():
+    print("go information:")
+
+    path = which("go")
+    print(f"  path={path}")
+
+    cmd = subprocess.run([path, "version"], capture_output=True, text=True)
+    # output is `go version go1.21.5 darwin/arm64`, we want the version and architecture
+    version = cmd.stdout.rstrip().split()
+    print(f"  version={version[2]}")
+    print(f"  architecture={version[3]}")
+
+
+def main():
+    go_version()
+
+
+if __name__ == "__main__":
+    main()