Update docker files and cirrus config

- Ubuntu focal is the lowest LTS release that we can support with only
  distro packages (e.g. no rustup).
- Remove tsan from Cirrus (it's not working currently, and also not really
  important).
- Remove Centos (it passes tests but I'm not sure it's worth adding; there
  isn't even an official docker image for CentOS Stream).

docker/jammy-tsan.Dockerfile

@@ -0,0 +1,45 @@
+FROM ubuntu:jammy
+LABEL org.opencontainers.image.source=https://github.com/fish-shell/fish-shell
+
+ENV LANG C.UTF-8
+ENV LC_ALL C.UTF-8
+
+RUN apt-get update \
+  && apt-get -y install \
+    build-essential \
+    cmake \
+    clang \
+    gettext \
+    git \
+    libpcre2-dev \
+    locales \
+    ninja-build \
+    python3 \
+    python3-pexpect \
+    sudo \
+    tmux \
+  && locale-gen en_US.UTF-8 \
+  && apt-get clean
+
+RUN groupadd -g 1000 fishuser \
+  && useradd -p $(openssl passwd -1 fish) -d /home/fishuser -m -u 1000 -g 1000 fishuser \
+  && adduser fishuser sudo \
+  && mkdir -p /home/fishuser/fish-build \
+  && mkdir /fish-source \
+  && chown -R fishuser:fishuser /home/fishuser /fish-source
+
+USER fishuser
+WORKDIR /home/fishuser
+
+RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs > /tmp/rustup.sh \
+  && sh /tmp/rustup.sh -y --default-toolchain nightly --component rust-src
+
+COPY fish_run_tests.sh /
+
+ENV \
+    RUSTFLAGS=-Zsanitizer=thread \
+    RUSTDOCFLAGS=-Zsanitizer=thread \
+    FISH_CI_SAN=1
+
+CMD . ~/.cargo/env \
+  && /fish_run_tests.sh -DTSAN=1 -DRust_CARGO_TARGET=x86_64-unknown-linux-gnu