ci: use sccache v0.10.0 with C++20 (#16183)

Author: scotthart

ci/cloudbuild/dockerfiles/fedora-latest-cxx20.Dockerfile

@@ -179,7 +179,7 @@ RUN curl -fsSL https://github.com/grpc/grpc/archive/v1.81.0.tar.gz | \
     cd /var/tmp && rm -fr build
 
 WORKDIR /var/tmp/sccache
-RUN curl -fsSL https://github.com/mozilla/sccache/releases/download/v0.15.0/sccache-v0.15.0-x86_64-unknown-linux-musl.tar.gz | \
+RUN curl -fsSL https://github.com/mozilla/sccache/releases/download/v0.10.0/sccache-v0.10.0-x86_64-unknown-linux-musl.tar.gz | \
     tar -zxf - --strip-components=1 && \
     mkdir -p /usr/local/bin && \
     mv sccache /usr/local/bin/sccache && \