fix sporadic failures to load DLLs by lazy loading them

[tgummerer]

On Windows DLL loading sometimes fails for spurious reasons. The panic is always in the following form:

syscall.MustLoadDLL(...)
	/opt/hostedtoolcache/go/1.21.1/x64/src/syscall/dll_windows.go:94
github.com/atotto/clipboard.init()
	/home/runner/go/pkg/mod/github.com/atotto/clipboard@v0.1.4/clipboard_windows.go:22 +0x347

This appears to be happening while loading the application, and was a frequent issue in CI tests in github.com/pulumi/pulumi. We can fix this by lazy loading the DLLs instead. We've been using this fix in our go.mod, using a replace statement (see pulumi/pulumi#17410), but would love to get this upstreamed, so we can remove that replace, and hopefully it helps others as well.