Add support for Postgres 18 and update default version

[otakakot]

Hello!

Since version 18.0.0 was supported at https://github.com/zonkyio/embedded-postgres-binaries, I implemented an update to version 18, referencing #159.

I also updated the default values ​​in the README.md, which had been overlooked.
Additionally, there were two "Version" entries in the table, so I removed one.

[otakakot]

https://github.com/fergusstrange/embedded-postgres/actions/runs/19267039257/job/55085300558?pr=162

The Nancy vulnerability scan failed due to the recent requirement for authentication on OSS Index.

https://ossindex.sonatype.org/doc/auth-required

[otakakot]

https://circleci.com/gh/fergusstrange/embedded-postgres/472

This test appears to have failed in the arm64 environment.
However, the test was successful in my development environment, an M1 Mac.
I have included the relevant information below.

❯ uname -m
arm64

❯ go version
go version go1.25.4 darwin/arm64

❯ cd platform-test && go test -v -run Test_AllMajorVersions/MajorVersion_18 ./...

Log Details

=== RUN   Test_AllMajorVersions
=== RUN   Test_AllMajorVersions/MajorVersion_18.0.0
The files belonging to this database system will be owned by user "otakakot".
This user must also own the server process.

The database cluster will be initialized with this locale configuration:
  locale provider:   libc
  LC_COLLATE:  ja_JP.UTF-8
  LC_CTYPE:    UTF-8
  LC_MESSAGES: ja_JP.UTF-8
  LC_MONETARY: ja_JP.UTF-8
  LC_NUMERIC:  ja_JP.UTF-8
  LC_TIME:     ja_JP.UTF-8
The default database encoding has accordingly been set to "UTF8".
initdb: could not find suitable text search configuration for locale "UTF-8"
The default text search configuration will be set to "simple".

Data page checksums are enabled.

creating directory /var/folders/8y/_8g8cqrj7pd90q3wd4bsxm_00000gp/T/embedded_postgres_tests3036903723/18.0.0/data ... ok
creating subdirectories ... ok
selecting dynamic shared memory implementation ... posix
selecting default "max_connections" ... 100
selecting default "shared_buffers" ... 128MB
selecting default time zone ... Asia/Tokyo
creating configuration files ... ok
running bootstrap script ... ok
performing post-bootstrap initialization ... ok
syncing data to disk ... ok

Success. You can now start the database server using:

    /var/folders/8y/_8g8cqrj7pd90q3wd4bsxm_00000gp/T/embedded_postgres_tests3036903723/18.0.0/bin/pg_ctl -D /var/folders/8y/_8g8cqrj7pd90q3wd4bsxm_00000gp/T/embedded_postgres_tests3036903723/18.0.0/data -l logfile start

waiting for server to start....2025-11-11 23:05:30.366 JST [26279] LOG:  starting PostgreSQL 18.0 on x86_64-apple-darwin23.6.0, compiled by Apple clang version 16.0.0 (clang-1600.0.26.6), 64-bit
2025-11-11 23:05:30.371 JST [26279] LOG:  listening on IPv6 address "::1", port 5555
2025-11-11 23:05:30.371 JST [26279] LOG:  listening on IPv4 address "127.0.0.1", port 5555
2025-11-11 23:05:30.372 JST [26279] LOG:  listening on Unix socket "/tmp/.s.PGSQL.5555"
2025-11-11 23:05:30.397 JST [26285] LOG:  database system was shut down at 2025-11-11 23:05:29 JST
2025-11-11 23:05:30.403 JST [26279] LOG:  database system is ready to accept connections
 done
server started
waiting for server to shut down....2025-11-11 23:05:30.578 JST [26279] LOG:  received fast shutdown request
2025-11-11 23:05:30.579 JST [26279] LOG:  aborting any active transactions
2025-11-11 23:05:30.579 JST [26292] FATAL:  terminating connection due to administrator command
2025-11-11 23:05:30.581 JST [26279] LOG:  background worker "logical replication launcher" (PID 26288) exited with exit code 1
2025-11-11 23:05:30.583 JST [26283] LOG:  shutting down
2025-11-11 23:05:30.583 JST [26283] LOG:  checkpoint starting: shutdown immediate
2025-11-11 23:05:30.586 JST [26283] LOG:  checkpoint complete: wrote 0 buffers (0.0%), wrote 3 SLRU buffers; 0 WAL file(s) added, 0 removed, 0 recycled; write=0.001 s, sync=0.001 s, total=0.003 s; sync files=2, longest=0.001 s, average=0.001 s; distance=0 kB, estimate=0 kB; lsn=0/1787288, redo lsn=0/1787288
2025-11-11 23:05:30.593 JST [26279] LOG:  database system is shut down
 done
server stopped
--- PASS: Test_AllMajorVersions (22.97s)
    --- PASS: Test_AllMajorVersions/MajorVersion_18.0.0 (22.97s)
PASS
ok      github.com/fergusstrange/embedded-postgres/platform-test        23.346s

[fergusstrange]

Hey thanks for the changes. I'll merge this in broken as I don't see any of these issues as related to your change. I'll look to fix up both tests before I cut a release however. If you beat me to it, you can raise a separate PR to look into the arm64 tests?

Thanks

[fergusstrange]

Looks like Mac ARM64 & Postgres 18 requires Rosetta 2, which I added to the circleCI build. I think there are probably native binaries now so I'll look to update this over time.

I'll document the Rosetta behaviour in the README for now.

Release cut @ https://github.com/fergusstrange/embedded-postgres/releases/tag/v1.33.0

Enjoy