pass: use go build constraint

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

Author: crazy-max

pass/cmd/main.go

@@ -1,3 +1,5 @@
+//go:build unix
+
 package main
 
 import (

pass/pass.go

@@ -1,3 +1,5 @@
+//go:build unix
+
 // Package pass implements a `pass` based credential helper. Passwords are stored
 // as arguments to pass of the form: "$PASS_FOLDER/base64-url(serverURL)/username".
 // We base64-url encode the serverURL, because under the hood pass uses files and

pass/pass_test.go

@@ -1,3 +1,5 @@
+//go:build unix
+
 package pass
 
 import (