RFR: 8344219: Remove calls to SecurityManager and doPrivileged in java.net.SocksSocketImpl after JEP 486 integration

[Volkan Yazıcı]

Removes `SecurityManager` et al. from `SocksSocketImpl`. `tier2` tests have passed – CI run link is available in the ticket.

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Commit messages:
 - 8344219: Remove `SM` et al. from `SocksSocketImpl`

Changes: https://git.openjdk.org/jdk/pull/22271/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22271&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8344219
  Stats: 61 lines in 1 file changed: 0 ins; 53 del; 8 mod
  Patch: https://git.openjdk.org/jdk/pull/22271.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22271/head:pull/22271

PR: https://git.openjdk.org/jdk/pull/22271