rust: Fix cargo clippy false positives

Add allow attributes for intentional patterns in pvverify and pvsecret.

Command line used to get the findings:

  $ clippy --all-features -- --cap-lints=warn
  ...
  help: remove this field
    --> pvverify/src/cli.rs:22:5
     |
  22 |     version: (),
     |     ^^^^^^^^^^^
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#manual_non_exhaustive
     = note: `#[warn(clippy::manual_non_exhaustive)]` on by default
  help: use the `#[non_exhaustive]` attribute instead
     |
  16 + #[non_exhaustive]
  17 | pub struct CliOptions {
     |

  warning: struct `AddSecretOptComb` is never constructed
     --> pvsecret/src/cli.rs:313:12
      |
  313 | pub struct AddSecretOptComb<'a> {
      |            ^^^^^^^^^^^^^^^^
      |
      = note: `-W dead-code` implied by `-W unused`
      = help: to override `-W unused` add `#[expect(dead_code)]` or `#[allow(dead_code)]`

  warning: struct `ListSecretOptComb` is never constructed
     --> pvsecret/src/cli.rs:355:12
      |
  355 | pub struct ListSecretOptComb<'a> {
      |            ^^^^^^^^^^^^^^^^^

  warning: struct `RetrSecretOptionsComb` is never constructed
     --> pvsecret/src/cli.rs:490:12
      |
  490 | pub struct RetrSecretOptionsComb<'a> {
      |            ^^^^^^^^^^^^^^^^^^^^^

Assisted-by: IBM Bob:1.0.4
Reviewed-by: Timo Keller <tkeller@linux.ibm.com>
Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Signed-off-by: Marc Hartmayer <marc@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>

rust/pvsecret/src/cli.rs

@@ -310,6 +310,9 @@ pub struct AddSecretOpt {
 }
 
 #[derive(Debug)]
+// Allow dead_code to suppress false positive: struct fields are accessed via From trait
+// implementation and used in cmd/add.rs, but clippy doesn't detect this indirect usage pattern
+#[allow(dead_code)]
 pub struct AddSecretOptComb<'a> {
     pub input: &'a str,
     pub force: bool,
@@ -352,6 +355,9 @@ pub struct ListSecretOpt {
 }
 
 #[derive(Debug)]
+// Allow dead_code to suppress false positive: struct fields are accessed via From trait
+// implementation and used in cmd/list.rs, but clippy doesn't detect this indirect usage pattern
+#[allow(dead_code)]
 pub struct ListSecretOptComb<'a> {
     pub output: &'a str,
     pub format: ListSecretOutputType,
@@ -487,6 +493,9 @@ pub enum RetrOutFmt {
 }
 
 #[derive(Debug)]
+// Allow dead_code to suppress false positive: struct fields are accessed via From trait
+// implementation and used in cmd/retr.rs, but clippy doesn't detect this indirect usage pattern
+#[allow(dead_code)]
 pub struct RetrSecretOptionsComb<'a> {
     pub input: &'a str,
     pub output: &'a str,

rust/pvverify/src/cli.rs

@@ -13,6 +13,9 @@ static VERSION: OnceLock<String> = OnceLock::new();
 /// Tool to verify host-keys
 ///
 /// Tool to verify host-keys. Use this tool to verify the chain of trust for IBM Secure
+// Allow manual_non_exhaustive to suppress Clippy false positive as the version
+// field is used by Clap to generate the --version flag.
+#[allow(clippy::manual_non_exhaustive)]
 pub struct CliOptions {
     #[command(flatten)]
     pub certificate_args: CertificateOptions,