chore: update the version of rust used in the CI build (#5407)

Dockerfile_build

@@ -4,12 +4,7 @@
 # and verification, we can list the rust container as a prior build stage, and
 # then pull in the artifacts we need. There is an added benefit that tagged versions
 # also include minor releases, so 1.2 includes 1.2.1 and so on, for bugfix releases.
-#
-# Note: we are stuck on Rust version 1.58 for the time being until
-# this issue is fixed:
-#   https://github.com/rust-lang/rust/issues/97117
-# Since it blocks the ARM64 build of InfluxDB.
-FROM rust:1.63 as RUSTBUILD
+FROM rust:1.68 as RUSTBUILD
 
 FROM golang:1.19 as PKGCONFIG
 COPY go.mod go.sum /go/src/github.com/influxdata/flux/