RFR: 8325731: Installation instructions for Debian/Ubuntu don't mention autoconf

[Johannes Bechberger]

So I added autoconf besides build-essential. With both packages, `bash configure` is runnable.

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Commit messages:
 - 8325731: Installation instructions for Debian/Ubuntu don't mention autoconf

Changes: https://git.openjdk.org/jdk/pull/17826/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17826&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8325731
  Stats: 2 lines in 2 files changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/17826.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17826/head:pull/17826

PR: https://git.openjdk.org/jdk/pull/17826