fix(interop/Dockerfile.chromium): use selenium/standalone-chrome:115.0

Our WASM Webtransport interoperability tests previously used Chrome 112. This Chrome version fails
to connect to go-libp2p with quic-go v0.38.0. See libp2p/go-libp2p#2506 for
failure. This is due to quic-go v0.38.0 moving to the updated code point for HTTP datagrams. See
quic-go/quic-go#3588 for details.

This commit upgrades our interop tests to use Chrome 115.

interop-tests/Dockerfile.chromium

@@ -23,7 +23,7 @@ RUN --mount=type=cache,target=./target \
 RUN --mount=type=cache,target=./target \
     mv ./target/release/wasm_ping /usr/local/bin/testplan
 
-FROM selenium/standalone-chrome:112.0
+FROM selenium/standalone-chrome:115.0
 COPY --from=builder /usr/local/bin/testplan /usr/local/bin/testplan
 
 ENV RUST_BACKTRACE=1