cksum: Remove redundant SHA3 tests (fixes PR uutils#8948 review feedback)

- Remove test_sha3_with_length() - redundant with test_sha3_single_file()
- Remove test_sha3_invalid_length() - redundant with test_sha_length_invalid() and test_sha_missing_length()
- Remove test_sha3_untagged() - redundant with test_untagged_sha3_single_file()
- Keep test_sha3_base64_output() - provides unique coverage for base64 output with SHA3

Addresses code review feedback from @cakebaker (Oct 31) on PR uutils#8948.
All 134 tests pass with no regressions.

Author: naoNao89

tests/by-util/test_cksum.rs

@@ -2668,70 +2668,6 @@ mod gnu_cksum_c {
     }
 }
 
-#[test]
-fn test_sha3_with_length() {
-    // Test SHA3-224
-    new_ucmd!()
-        .arg("-a")
-        .arg("sha3")
-        .arg("--length")
-        .arg("224")
-        .arg("lorem_ipsum.txt")
-        .succeeds()
-        .stdout_contains("SHA3-224 (lorem_ipsum.txt) = ");
-
-    // Test SHA3-256
-    new_ucmd!()
-        .arg("-a")
-        .arg("sha3")
-        .arg("--length")
-        .arg("256")
-        .arg("lorem_ipsum.txt")
-        .succeeds()
-        .stdout_contains("SHA3-256 (lorem_ipsum.txt) = ");
-
-    // Test SHA3-384
-    new_ucmd!()
-        .arg("-a")
-        .arg("sha3")
-        .arg("--length")
-        .arg("384")
-        .arg("lorem_ipsum.txt")
-        .succeeds()
-        .stdout_contains("SHA3-384 (lorem_ipsum.txt) = ");
-
-    // Test SHA3-512
-    new_ucmd!()
-        .arg("-a")
-        .arg("sha3")
-        .arg("--length")
-        .arg("512")
-        .arg("lorem_ipsum.txt")
-        .succeeds()
-        .stdout_contains("SHA3-512 (lorem_ipsum.txt) = ");
-}
-
-#[test]
-fn test_sha3_invalid_length() {
-    // Test SHA3 with invalid length (not 224, 256, 384, or 512)
-    new_ucmd!()
-        .arg("-a")
-        .arg("sha3")
-        .arg("--length")
-        .arg("128")
-        .arg("lorem_ipsum.txt")
-        .fails()
-        .stderr_contains("digest length for 'SHA3' must be 224, 256, 384, or 512");
-
-    // Test SHA3 without length
-    new_ucmd!()
-        .arg("-a")
-        .arg("sha3")
-        .arg("lorem_ipsum.txt")
-        .fails()
-        .stderr_contains("--algorithm=sha3 requires specifying --length 224, 256, 384, or 512");
-}
-
 #[test]
 fn test_sha3_base64_output() {
     // Test SHA3 with base64 output format
@@ -2746,19 +2682,6 @@ fn test_sha3_base64_output() {
         .stdout_contains("SHA3-256 (lorem_ipsum.txt) = ");
 }
 
-#[test]
-fn test_sha3_untagged() {
-    // Test SHA3 with untagged output
-    new_ucmd!()
-        .arg("--untagged")
-        .arg("-a")
-        .arg("sha3")
-        .arg("--length")
-        .arg("256")
-        .arg("lorem_ipsum.txt")
-        .succeeds();
-}
-
 /// The tests in this module check the behavior of cksum when given different
 /// checksum formats and algorithms in the same file, while specifying an
 /// algorithm on CLI or not.