Update Ubuntu images to 24.04

We don't have any specific reason to stay on 18.04, so upgrade to the
latest LTS version.

Author: tgross35

ci/docker/aarch64-unknown-linux-gnu/Dockerfile

@@ -1,4 +1,5 @@
-FROM ubuntu:18.04
+FROM ubuntu:24.04
+
 RUN apt-get update && \
     apt-get install -y --no-install-recommends \
     gcc libc6-dev ca-certificates \

ci/docker/arm-unknown-linux-gnueabi/Dockerfile

@@ -1,4 +1,5 @@
-FROM ubuntu:18.04
+FROM ubuntu:24.04
+
 RUN apt-get update && \
     apt-get install -y --no-install-recommends \
     gcc libc6-dev ca-certificates \

ci/docker/arm-unknown-linux-gnueabihf/Dockerfile

@@ -1,4 +1,5 @@
-FROM ubuntu:18.04
+FROM ubuntu:24.04
+
 RUN apt-get update && \
     apt-get install -y --no-install-recommends \
     gcc libc6-dev ca-certificates \

ci/docker/armv7-unknown-linux-gnueabihf/Dockerfile

@@ -1,4 +1,5 @@
-FROM ubuntu:18.04
+FROM ubuntu:24.04
+
 RUN apt-get update && \
     apt-get install -y --no-install-recommends \
     gcc libc6-dev ca-certificates \

ci/docker/i686-unknown-linux-gnu/Dockerfile

@@ -1,4 +1,5 @@
-FROM ubuntu:18.04
+FROM ubuntu:24.04
+
 RUN apt-get update && \
     apt-get install -y --no-install-recommends \
     gcc-multilib libc6-dev ca-certificates

ci/docker/mips-unknown-linux-gnu/Dockerfile

@@ -1,4 +1,4 @@
-FROM ubuntu:18.04
+FROM ubuntu:24.04
 
 RUN apt-get update && \
     apt-get install -y --no-install-recommends \

ci/docker/mips64-unknown-linux-gnuabi64/Dockerfile

@@ -1,4 +1,5 @@
-FROM ubuntu:18.04
+FROM ubuntu:24.04
+
 RUN apt-get update && \
     apt-get install -y --no-install-recommends \
     ca-certificates \

ci/docker/mips64el-unknown-linux-gnuabi64/Dockerfile

@@ -1,4 +1,5 @@
-FROM ubuntu:18.04
+FROM ubuntu:24.04
+
 RUN apt-get update && \
     apt-get install -y --no-install-recommends \
     ca-certificates \

ci/docker/mipsel-unknown-linux-gnu/Dockerfile

@@ -1,4 +1,4 @@
-FROM ubuntu:18.04
+FROM ubuntu:24.04
 
 RUN apt-get update && \
     apt-get install -y --no-install-recommends \

ci/docker/powerpc-unknown-linux-gnu/Dockerfile

@@ -1,4 +1,4 @@
-FROM ubuntu:18.04
+FROM ubuntu:24.04
 
 RUN apt-get update && \
     apt-get install -y --no-install-recommends \