bump docker ubuntu version to upgrade needed packages (#28)

Dockerfile

@@ -1,20 +1,14 @@
-FROM ubuntu:22.04
+FROM ubuntu:24.04
 
-# Specifically use bats 1.7.0
-# Remove git when we're done with it.
-# Test runner needs jq.
+# Ubuntu 24.04 'noble numbat' gets us:
+# gawk v5.2.1           https://launchpad.net/ubuntu/noble/+source/gawk
+# jq   v1.7.1           https://launchpad.net/ubuntu/noble/+source/jq
+# bats v1.10.0          https://launchpad.net/ubuntu/noble/+source/bats
 
-RUN apt-get update                                   && \
-    apt-get install -y gawk jq git                   && \
-    git clone https://github.com/bats-core/bats-core && \
-    cd bats-core                                     && \
-    git checkout v1.7.0                              && \
-    bash ./install.sh /usr/local                     && \
-    cd ..                                            && \
-    rm -rf ./bats-core                               && \
-    apt-get remove -y git                            && \
-    apt-get purge --auto-remove -y                   && \
-    apt-get clean                                    && \
+RUN apt-get update                    && \
+    apt-get install -y gawk jq bats   && \
+    apt-get purge --auto-remove -y    && \
+    apt-get clean                     && \
     rm -rf /var/lib/apt/lists/*
 
 WORKDIR /opt/test-runner