Pin golang Docker tag to 0ece421 (#26)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| golang | stage | pinDigest |  -> `0ece421` |

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otlp-bench/bench-setup/Dockerfile.custom

@@ -3,7 +3,7 @@ FROM alpine:3.23@sha256:51183f2cfa6320055da30872f211093f9ff1d3cf06f39a0bdb212314
 RUN apk --update add ca-certificates
 
 
-FROM golang:1.25 AS build-stage
+FROM golang:1.25@sha256:0ece421d4bb2525b7c0b4cad5791d52be38edf4807582407525ca353a429eccc AS build-stage
 
 WORKDIR /build