Bump to rust 1.78

arm64.dockerfile

 ## This file can be used to build arm64 Linux versions of a Bevy project
 
 FROM r.lcr.gr/microhacks/msdfgen-builder:arm64 AS msdfgen
-FROM rust:1.70.0-slim
+FROM rust:1.78.0-slim
 
 COPY --from=msdfgen /usr/bin/msdf-atlas-gen /usr/bin/msdf-atlas-gen
 

x86.dockerfile

 ## This file can be used to build x86 Linux, x86 Windows and Wasm versions of a Bevy project
 FROM r.lcr.gr/microhacks/msdfgen-builder:latest AS msdfgen
-FROM rust:1.70.0-slim AS trunkbuild
+FROM rust:1.78.0-slim AS trunkbuild
 RUN cargo install --locked trunk && \
     rm -rf ~/.cargo/registry/{cache,src}
 
-FROM rust:1.70.0-slim
+FROM rust:1.78.0-slim
 
 COPY --from=msdfgen /usr/bin/msdf-atlas-gen /usr/bin/msdf-atlas-gen