crypto: psa_crypto: mark expected_shared_secret as __unused

Mark expected_shared_secret as __unused so the variable is always defined
but does not trigger compiler warnings when CONFIG_TEST_WRAPPED_KEYS is
enabled and the value is not referenced.

This aligns with Zephyr coding conventions for conditionally used constants
and avoids build errors in tests compiled with -Werror.

Signed-off-by: Aasim Shaik <[email protected]>

Author: Aasimshaik11

tests/crypto/psa_crypto/src/key_agreement.c

@@ -28,13 +28,11 @@ static const uint8_t server_public_key[] = {
 	0x8D, 0x49, 0x85, 0x8C, 0x7A, 0x9F, 0xC1, 0x46, 0xDA, 0xCC, 0x96,
 	0xEF, 0x6E, 0xD4, 0xDA, 0x71, 0xBF, 0xED, 0x32, 0x0D, 0x76,
 };
-#if  !IS_ENABLE(CONFIG_TEST_WRAPPED_KEYS)
-	static const uint8_t expected_shared_secret[] = {
-		0xF2, 0xE6, 0x0E, 0x1C, 0xB7, 0x64, 0xBC, 0x48, 0xF2, 0x9D, 0xBB,
-		0x12, 0xFB, 0x12, 0x17, 0x31, 0x32, 0x1D, 0x79, 0xAF, 0x0A, 0x9F,
-		0xAB, 0xAD, 0x34, 0x05, 0xA2, 0x07, 0x39, 0x9C, 0x5F, 0x15,
-	};
-#endif
+static const uint8_t expected_shared_secret[] __unused = {
+	0xF2, 0xE6, 0x0E, 0x1C, 0xB7, 0x64, 0xBC, 0x48, 0xF2, 0x9D, 0xBB,
+	0x12, 0xFB, 0x12, 0x17, 0x31, 0x32, 0x1D, 0x79, 0xAF, 0x0A, 0x9F,
+	0xAB, 0xAD, 0x34, 0x05, 0xA2, 0x07, 0x39, 0x9C, 0x5F, 0x15,
+};
 ZTEST(psa_crypto_test, test_key_agreement_ecdh_25519)
 {
 	uint8_t shared_secret_buf[32];