docs: add warning about kaniko lacking maintainers

kaniko outputs each tag on a new line, so users that push multiple tags
at once would get an error as the output wasn't prepared to handle multi-line
text

.github/workflows/pr.yml

@@ -10,4 +10,4 @@ jobs:
         with:
           fetch-depth: 0
       - name: Run commitsar
-        uses: docker://aevea/commitsar@sha256:8d2db4e430dd06e3fcde173add43dada80b37150ba1191a69cda1c0bcdba9cb1
+        uses: docker://aevea/commitsar@sha256:e4aed72de9a00b990a53c678ad51fbe9bd04e127a617d10beab0ef0204b1dfa0

.github/workflows/release.yml

@@ -15,7 +15,7 @@ jobs:
           fetch-depth: 0
 
       - name: Release Notary Action
-        uses: docker://aevea/release-notary@sha256:b77e86ce9ce4b0c8774cdb3b807b756d1d6139d73aca74388560250de259be4e
+        uses: docker://aevea/release-notary@sha256:690915bf87458fd8eb1e1ff0be34b33377f920eda3f38b96c62ecbf897c831f4
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         with:

Dockerfile

@@ -2,7 +2,7 @@ FROM alpine as certs
 
 RUN apk --update add ca-certificates
 
-FROM gcr.io/kaniko-project/executor:v1.21.1-debug
+FROM gcr.io/kaniko-project/executor:v1.23.2-debug
 
 SHELL ["/busybox/sh", "-c"]
 

README.md

@@ -1,5 +1,8 @@
 # Kaniko image builder
 
+> [!WARNING]  
+> The kaniko project no longer seems to [have maintainers](https://github.com/GoogleContainerTools/kaniko/issues/3348). Keep this in mind before deciding to use kaniko as your image builder.
+
 This Action uses the [kaniko](https://github.com/GoogleContainerTools/kaniko) executor instead of the docker daemon. Kaniko builds the image
 by extracting the filesystem of the base image, making the changes in the user space, snapshotting any change and appending it to the base
 image filesystem.

entrypoint.sh

@@ -102,7 +102,9 @@ eval "${kaniko_cmd}"
 
 echo "image=$IMAGE" >> "$GITHUB_OUTPUT"
 echo "digest=$(cat /kaniko/digest)" >> "$GITHUB_OUTPUT"
-echo "image-tag-digest=$(cat /kaniko/image-tag-digest)" >> "$GITHUB_OUTPUT"
+echo "image-tag-digest<<EOF" >>"$GITHUB_OUTPUT"
+echo "$(cat /kaniko/image-tag-digest)" >>"$GITHUB_OUTPUT"
+echo 'EOF' >>"$GITHUB_OUTPUT"
 
 
 if [ -n "$INPUT_SKIP_UNCHANGED_DIGEST" ]; then