Zig's std.os.getenv is linux-only and does not compile on windows.

[sarahkittyy]

Description

This program cannot compile on Windows because std.os.getenv is not cross-platform. It should be replaced with std.process.getEnvVarOwned.

How to Reproduce the Bug

• Run zig build on windows.

Additional Context

D:\zig\lib\std\os.zig:1910:9: error: std.os.getenv is unavailable for Windows because environment string is in WTF-16 format. See std.process.getEnvVarOwned for cross-platform API or std.os.getenvW for Windows-specific API.
        @compileError("std.os.getenv is unavailable for Windows because environment string is in WTF-16 format. See std.process.getEnvVarOwned for cross-platform API or std.os.getenvW for Windows-specific API.");
        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
referenced by:
    getOrInitIdentity: src\gossip\cmd.zig:19:28
    initSpy: src\gossip\cluster_info.zig:62:30
    remaining reference traces hidden; use '-freference-trace' to see all reference traces