chore(deps): update dependency sigstore/cosign to v2.4.0 (#877)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

jenkins-agents/jenkins-agent-cosign/Dockerfile

@@ -2,7 +2,7 @@
 FROM registry.access.redhat.com/ubi9/ubi:9.4-1123.1719560047@sha256:081c96d1b1c7cd1855722d01f1ca53360510443737b1eb33284c6c4c330e537c AS builder
 
 # renovate: datasource=github-releases depName=sigstore/cosign
-ARG COSIGN_VERSION=v2.2.4
+ARG COSIGN_VERSION=v2.4.0
 RUN curl -L "https://github.com/sigstore/cosign/releases/download/${COSIGN_VERSION}/cosign-linux-amd64" -o /usr/local/bin/cosign && \
     chmod +x /usr/local/bin/cosign && \
     cosign version