remove march=native from pgvector Makefile's OPTFLAGS

[Bodobolero]

Problem

By default, pgvector compiles with -march=native on some platforms for best performance. However, this can lead to Illegal instruction errors if trying to run the compiled extension on a different machine.

I had this problem when trying to run the Neon compute docker image on MacOS with Apple Silicon with Rosetta.

see https://github.com/pgvector/pgvector/blob/ff9b22977e3ef19866d23a54332c8717f258e8db/README.md?plain=1#L1021

Summary of changes

Pass OPTFLAGS="" to make.

[hlinnaka]

-march=native is problematic, but I wonder if we should target some more recent chipset, with e.g. AVX512 support? We are also planning to switch to arm, so maybe revisit this after the switch though.

[github-actions]

3108 tests run: 2981 passed, 0 failed, 127 skipped (full report)

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Flaky tests (2)

Postgres 15

• test_crafted_wal_end[last_wal_record_xlog_switch]: debug
• test_timeline_deletion_with_files_stuck_in_upload_queue: debug

Code coverage* (full report)

• functions: 31.4% (6451 of 20544 functions)
• lines: 48.3% (49876 of 103270 lines)

* collected from Rust tests only

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_{The comment gets automatically updated with the latest test results
8110da2 at 2024-05-23T10:16:06.818Z :recycle:}

[Bodobolero]

-march=native is problematic, but I wonder if we should target some more recent chipset, with e.g. AVX512 support? We are also planning to switch to arm, so maybe revisit this after the switch though.

I plan to do an investigation with respect to the various toolchains on compile flags that optimize for architectures and the impact on performance (if I can get this task added to our team's plan).
For now I would just remove the '-march=native' to get us going.