ci(central): remove workflow version update automation

[andrewazores]

Related to #92
Related to #338

Removes the version updating automation from the workflow since this is not working with the branch protection rules we have set for main and the github-actions[bot] pseudo-user, nor the PAT that we use for other similar updates with web-client submodules.

For now this is left as a manual step that publishes the current (probably -SNAPSHOT) version from main directly to central. Once that's working I'll follow up with another PR to merge that workflow into the pre-existing one that builds and publishes to the GitHub Maven Packages repository, so that this new action for publishing to Maven Central is just an automatic addition to our existing release workflow process.

[github-actions]

ARCH	IMAGE
amd64	ghcr.io/cryostatio/cryostat-core:pr-339-d6edde406259561482041a4a98b6d64205f73917-linux-amd64
arm64	ghcr.io/cryostatio/cryostat-core:pr-339-d6edde406259561482041a4a98b6d64205f73917-linux-arm64
cryostat3-java17_amd64	ghcr.io/cryostatio/cryostat-core:pr-339-d6edde406259561482041a4a98b6d64205f73917-linux-amd64-java17
cryostat3-java17_arm64	ghcr.io/cryostatio/cryostat-core:pr-339-d6edde406259561482041a4a98b6d64205f73917-linux-arm64-java17

To run smoketest:

# amd64
CRYOSTAT_IMAGE=ghcr.io/cryostatio/cryostat-core:pr-339-d6edde406259561482041a4a98b6d64205f73917-linux-amd64 sh smoketest.sh

# or arm64
CRYOSTAT_IMAGE=ghcr.io/cryostatio/cryostat-core:pr-339-d6edde406259561482041a4a98b6d64205f73917-linux-arm64 sh smoketest.sh

# or cryostat3-java17-amd64
CRYOSTAT3_java17amd64_IMAGE=ghcr.io/cryostatio/cryostat-core:pr-339-d6edde406259561482041a4a98b6d64205f73917-linux-amd64-java17 sh smoketest.sh

# or cryostat3-java17-arm64
CRYOSTAT3_java17arm64_IMAGE=ghcr.io/cryostatio/cryostat-core:pr-339-d6edde406259561482041a4a98b6d64205f73917-linux-arm64-java17 sh smoketest.sh