added ubuntu image for Gitea actions

gitea-runner/Dockerfile

@@ -1,4 +1,5 @@
-FROM alpine:3.24 AS runner
+ARG ALPINE_VERSION=3.24
+FROM alpine:${ALPINE_VERSION} AS runner
 RUN echo "@testing https://dl-cdn.alpinelinux.org/alpine/edge/testing" >> /etc/apk/repositories
 RUN --mount=type=cache,target=/var/cache/apk apk update
 RUN --mount=type=cache,target=/var/cache/apk apk add gitea-runner@testing nodejs docker shadow
@@ -9,7 +10,18 @@ USER gitea-runner
 WORKDIR /var/lib/gitea-runner
 CMD ["/usr/bin/gitea-runner", "daemon", "--config", "/etc/gitea-runner/config.yaml"]
 
-FROM debian:stable-slim AS debian
+ARG DEBIAN_VERSION=13
+FROM debian:${DEBIAN_VERSION}-slim AS debian
+RUN --mount=type=cache,target=/var/cache/apt,sharing=locked \
+    --mount=type=cache,target=/var/lib/apt,sharing=locked \
+    apt update &&\
+    apt install -y nodejs unzip git
+RUN useradd gitea-runner -d /var/lib/gitea-runner -u 555 -r
+USER gitea-runner
+WORKDIR /var/lib/gitea-runner
+
+ARG UBUNTU_VERSION=26.04
+FROM ubuntu:${UBUNTU_VERSION} AS ubuntu
 RUN --mount=type=cache,target=/var/cache/apt,sharing=locked \
     --mount=type=cache,target=/var/lib/apt,sharing=locked \
     apt update &&\
@@ -53,7 +65,7 @@ RUN ln -s /opt/x-tools/arm-unknown-linux-musleabihf/bin/arm-unknown-linux-muslea
 RUN ln -s /opt/x-tools/x86_64-w64-mingw32/bin/x86_64-w64-mingw32-gcc /usr/local/bin/x86_64-pc-windows-gnu-gcc
 RUN useradd gitea-runner -u 555 -s /bin/bash -m -d /var/lib/gitea-runner
 
-FROM alpine:3.24 AS pnpm
+FROM alpine:${ALPINE_VERSION} AS pnpm
 RUN --mount=type=cache,target=/var/cache/apk apk update
 RUN --mount=type=cache,target=/var/cache/apk apk add nodejs shadow git pnpm
 RUN adduser -S -u 555 -h /var/lib/gitea-runner gitea-runner