Bump frolvlad/alpine-python3 in /benchmarks/docker (#1111)

Bumps frolvlad/alpine-python3 from `82d9ef3` to `48a2207`.

---
updated-dependencies:
- dependency-name: frolvlad/alpine-python3
  dependency-type: direct:production
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

benchmarks/docker/Dockerfile-benchmark

@@ -1,4 +1,4 @@
-FROM frolvlad/alpine-python3@sha256:82d9ef30b6b3cca35cee157a2e0d2e179be8e6a18c7621e99dd33fbf17a97e55
+FROM frolvlad/alpine-python3@sha256:48a2207f44c768a534ec2b6379707767c96e5aaccb1fc2b73442a26bf3d74116
 
 RUN apk add docker openrc
 RUN rc-update add docker boot