Upgrade Ubuntu to 22.04 Jammy Jellyfish

Currently, Ubuntu's Software & Updates application does not detect the upgrade for Jammy Jellyfish 22.04, released on 22/4.
This temporary fix exposes 22.04 stable to Ubuntu so it can upgrade.

1. Changing the upgrade link

Edit /etc/update-manager/meta-release in your preferred editor(I'm using gedit)
You should see something like this:

# default location for the meta-release file

[METARELEASE]
URI = https://changelogs.ubuntu.com/meta-release
URI_LTS = https://changelogs.ubuntu.com/meta-release-lts
URI_UNSTABLE_POSTFIX = -development
URI_PROPOSED_POSTFIX = -proposed

Change URI = https://changelogs.ubuntu.com/meta-release to URI = https://raw.githubusercontent.com/czlucius/ubuntu-upgrade-jammy/main/meta_release_jammy.
This link is pointing to the meta_release_jammy file of this repo: https://github.com/czlucius/ubuntu-upgrade-jammy/blob/main/meta_release_jammy. (you can compare with https://changelogs.ubuntu.com/meta-release if you're concerned about it's safety)

Save the file.

2. Check and install the upgrade

In a terminal window, type do-release-upgrade to fetch the upgrades from Ubuntu(Canonical)'s servers. Accept all prompts and the upgrade should be installed.

Thanks!
Star/watch the repo if this is helpful.

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Upgrade Ubuntu to Jammy Jellyfish 22.04 through official sources, since upgrade manager currently does not detect the upgrade.