[8.x] Update .backportrc.json

[jmikell821]

Adds 8.17 to list of backports.

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[lcawl]

LGTM

[nastasha-solomon]

Approving this since @lcawl gave the thumbs up. But to be transparent, I don't fully understand why we're updating this file in the 8.x branch and how it'll affect PRs that are merged directly into 8.x instead of main.

[lcawl]

But to be transparent, I don't fully understand why we're updating this file in the 8.x branch and how it'll affect PRs that are merged directly into 8.x instead of main.

Per https://github.com/sorenlouv/backport/blob/main/docs/config-file-options.md#project-config-backportrcjson that section of the file is just the "List of target branches the user can select interactively". Thus if someone has the 8.x branch checked out and runs the backport command, it'll now include v8.17 in the list of possible target branches.

[nastasha-solomon]

Oh, nice. I didn't know that file existed and completely forgot about our internal backport tool (we've mainly worked with Mergify 😅). Thanks for sharing the docs, @lcawl. The updates @jmikell821 made make much more sense now.