RFR: 1905: Notify graal mailing list for JVMCI related PRs

[Erik Joelsson]

Add the new `graal` label to the auto label configuration for jvmci related paths. This will include the graal-dev mailinglist in PRs touching files in those paths.

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Commit messages:
 - SKARA-1905

Changes: https://git.openjdk.org/skara/pull/1520/files
 Webrev: https://webrevs.openjdk.org/?repo=skara&pr=1520&range=00
  Issue: https://bugs.openjdk.org/browse/SKARA-1905
  Stats: 6 lines in 1 file changed: 6 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/skara/pull/1520.diff
  Fetch: git fetch https://git.openjdk.org/skara.git pull/1520/head:pull/1520

PR: https://git.openjdk.org/skara/pull/1520