fileperms: newer Go 1.13+ octal literal format

Problem: While removing cgroupsv1 code, I noticed my neovim Go config
automatically changed fileperms to the new octal format and I didn't
want that polluting my diffs.

Decision: I thought it best to switch to the new octal format in a dedicated PR.

Action:
- Cursor switched to new octal format for all fileperm ocurrences in Go
 source and test files.
- vendor/, docs/ and non-Go files were ignored.
- Reviewed manually.

Ref: https://go.dev/ref/spec#Go_1.13

Signed-off-by: Lokesh Mandvekar <lsm5@redhat.com>

pkg/machine/e2e/basic_test.go

@@ -229,7 +229,7 @@ var _ = Describe("run basic podman commands", func() {
 
 		testString := "abcdefg1234567"
 		testFile := "testfile"
-		err = os.WriteFile(filepath.Join(dir, testFile), []byte(testString), 0644)
+		err = os.WriteFile(filepath.Join(dir, testFile), []byte(testString), 0o644)
 		Expect(err).ToNot(HaveOccurred())
 
 		name := randomString()