fix(clustertool) fix shamir_threshold check (#29302)

**Description**
current implementation just checks the first line of the file as it
exits in the “else”

⚒️ Fixes  # <!--(issue)-->

**⚙️ Type of change**

- [ ] ⚙️ Feature/App addition
- [x] 🪛 Bugfix
- [ ] ⚠️ Breaking change (fix or feature that would cause existing
functionality to not work as expected)
- [ ] 🔃 Refactor of current code

**🧪 How Has This Been Tested?**
Local go test file. 

**📃 Notes:**
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**✔️ Checklist:**

- [ ] ⚖️ My code follows the style guidelines of this project
- [ ] 👀 I have performed a self-review of my own code
- [ ] #️⃣ I have commented my code, particularly in hard-to-understand
areas
- [ ] 📄 I have made corresponding changes to the documentation
- [ ] ⚠️ My changes generate no new warnings
- [ ] 🧪 I have added tests to this description that prove my fix is
effective or that my feature works
- [ ] ⬆️ I increased versions for any altered app according to semantic
versioning
- [ ] I made sure the title starts with `feat(chart-name):`,
`fix(chart-name):` or `chore(chart-name):`

**➕ App addition**

If this PR is an app addition please make sure you have done the
following.

- [ ] 🖼️ I have added an icon in the Chart's root directory called
`icon.png`

---

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clustertool/pkg/sops/checkencrypt.go

@@ -207,17 +207,15 @@ func shamCheck() {
         if strings.Contains(scanner.Text(), "shamir_threshold") {
             log.Debug().Msg("clusterenv contains shamir_threshold, continuing...")
             return
-        } else {
-            log.Error().Msg("clusterenv is NOT encrypted and encryption-check failed!\n DO NOT UPLOAD!")
-            os.Exit(1)
         }
     }
 
     if err := scanner.Err(); err != nil {
         log.Error().Err(err).Msgf("error reading file: %w", err)
     }
 
-    return
+    log.Error().Msg("clusterenv is NOT encrypted and encryption-check failed!\n DO NOT UPLOAD!")
+    os.Exit(1)
 }
 
 // filesToCheck returns a list of files to check for encryption based on the logic in .sops.yaml.