Do not pollute home directory with test data (#6371)

We can just write those files into /tmp

(cherry picked from commit 6c05b06)

Author: neonichu

Tests/CommandsTests/SwiftToolTests.swift

@@ -161,7 +161,7 @@ final class SwiftToolTests: CommandsTestCase {
 
             // custom .netrc file
             do {
-                let customPath = try fs.homeDirectory.appending(component: UUID().uuidString)
+                let customPath = try fs.tempDirectory.appending(component: UUID().uuidString)
                 try fs.writeFileContents(customPath) {
                     "machine mymachine.labkey.org login [email protected] password custom"
                 }
@@ -195,7 +195,7 @@ final class SwiftToolTests: CommandsTestCase {
 
             // custom .netrc file
             do {
-                let customPath = try fs.homeDirectory.appending(component: UUID().uuidString)
+                let customPath = try fs.tempDirectory.appending(component: UUID().uuidString)
                 try fs.writeFileContents(customPath) {
                     "machine mymachine.labkey.org login [email protected] password custom"
                 }