chore(deps): update alpine docker tag to v3.21 (#116)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| alpine | final | minor | `3.20` -> `3.21` |

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Dockerfile

@@ -17,7 +17,7 @@ RUN mage install
 
 # ---
 
-FROM alpine:3.20
+FROM alpine:3.21
 
 COPY --from=builder /go/bin/tss /usr/bin/tss