ci: chemenu-ci-pwsh image - PowerShell 7 and PSScriptAnalyzer for the pwsh job (#151)

Files changed:
- .gitea/pwsh-ci/Dockerfile
- .gitea/workflows/pwsh-ci-image.yml

.gitea/pwsh-ci/Dockerfile

@@ -0,0 +1,34 @@
+# The image the `pwsh` job of ci.yml runs in: Debian, PowerShell 7 and PSScriptAnalyzer,
+# plus what the tool preflight and the suite need (Gitea #151, D37). Built by
+# `.gitea/workflows/pwsh-ci-image.yml`, never by hand.
+FROM debian:trixie-slim
+
+ARG PWSH_VERSION
+
+# `nodejs` is for act_runner, which executes JavaScript actions (checkout) inside the job
+# container. `libicu76` is what PowerShell's .NET needs for culture data; `iconv` converts
+# the UTF-16 checksum list the PowerShell release publishes.
+RUN set -eu; \
+    test -n "$PWSH_VERSION"; \
+    apt-get update -qq; \
+    apt-get install -y --no-install-recommends \
+      ca-certificates curl git nodejs python3 python3-venv ripgrep libicu76; \
+    base="https://github.com/PowerShell/PowerShell/releases/download/v${PWSH_VERSION}"; \
+    tarball="powershell-${PWSH_VERSION}-linux-x64.tar.gz"; \
+    curl -fsSL -o "/tmp/${tarball}" "${base}/${tarball}"; \
+    curl -fsSL "${base}/hashes.sha256" | iconv -f UTF-16 -t UTF-8 | tr -d '\r' > /tmp/hashes.sha256; \
+    expected="$(grep -F "*${tarball}" /tmp/hashes.sha256 | cut -d' ' -f1)"; \
+    test -n "$expected"; \
+    echo "${expected}  /tmp/${tarball}" | sha256sum -c -; \
+    mkdir -p /opt/microsoft/powershell/7; \
+    tar -xzf "/tmp/${tarball}" -C /opt/microsoft/powershell/7; \
+    chmod +x /opt/microsoft/powershell/7/pwsh; \
+    ln -s /opt/microsoft/powershell/7/pwsh /usr/local/bin/pwsh; \
+    rm -rf /tmp/* /var/lib/apt/lists/*
+
+RUN pwsh -NoProfile -Command \
+      "Set-PSRepository PSGallery -InstallationPolicy Trusted; Install-Module PSScriptAnalyzer -Scope AllUsers -Force"
+
+LABEL org.opencontainers.image.title="chemenu-ci-pwsh" \
+      org.opencontainers.image.description="PowerShell 7 and PSScriptAnalyzer for chemenu's pwsh CI job" \
+      chemenu.pwsh-version="${PWSH_VERSION}"