chore!: drop next@11 support

[trentm]

next@11 does not get new releases, and only works on node 14 and 16,
which are EOL. It is failing in our CI TAV tests and it is not worth
the time digging into older versions.

---

Currently test-tav (next 14) and test-tav (next 16), i.e. the TAV tests of Next.js with Node v14 and v16, are failing with next@11. For example, from https://github.com/elastic/apm-agent-nodejs/actions/runs/6488426576/job/17620863144

...
node_tests_1  | -- installing ["react@^18.2.0","react-dom@^18.2.0","next@12.0.10"]
node_tests_1  | -- running test "node ../next.test.js" with next
node_tests_1  | -- required packages ["react@^17.0.2","react-dom@^17.0.2","next@11.1.4"]
node_tests_1  | -- installing ["react@^17.0.2","react-dom@^17.0.2","next@11.1.4"]
node_tests_1  | -- running test "node ../next.test.js" with next
node_tests_1  | -- detected failing command, flushing stdout...
node_tests_1  | TAP version 13
...
node_tests_1  | # -- dev server tests --
...
node_tests_1  | not ok 147 waitForServerReady request
node_tests_1  |   ---
node_tests_1  |     operator: equal
node_tests_1  |     expected: |-
node_tests_1  |       'GET /api/an-api-endpoint'
node_tests_1  |     actual: |-
node_tests_1  |       'GET unknown route'
node_tests_1  |     at: checkExpectedApmEvents (/app/test/instrumentation/modules/next/next.test.js:721:5)
node_tests_1  |     stack: |-
node_tests_1  |       Error: waitForServerReady request
node_tests_1  |           at Test.assert [as _assert] (/app/node_modules/tape/lib/test.js:479:48)
node_tests_1  |           at Test.strictEqual (/app/node_modules/tape/lib/test.js:643:7)
node_tests_1  |           at checkExpectedApmEvents (/app/test/instrumentation/modules/next/next.test.js:721:5)
...

I don't know what changed or when exactly, but I propose that it isn't worth digging into this because:

• Our Next.js support is still experimental/preview.
• The last next@11 release was '11.1.4': '2022-01-27T02:04:33.982Z',. (FWIW, the last next@12 release was '12.3.4': '2022-11-21T23:40:47.122Z',.)
• Unfortunately we don't support the latest 13.x minor versions. The current release is 13.5.4 and we only support to 13.2.x. If any time is to be spent on Next.js, it should be on supporting the latest and/or looking at better using and guiding users towards Next.js' built-in OpenTelemetry support.

Instead, let's drop next@11 support, so our builds can go green.

---

This change also reduces the number of next@12 and 13 versions tested, because the next TAV tests have become too long:

% ./dev-utils/ci-tav-slow-jobs.sh | tail
793 13m13s test-tav (@elastic/elasticsearch 14)
807 13m27s test-tav (elasticsearch 14)
814 13m34s test-tav (redis 14)
1002 16m42s test-tav (express 14)
1070 17m50s test-tav (graphql 14)
1110 18m30s test-tav (mysql2 14)
1127 18m47s test-tav (next 18)
1193 19m53s test-tav (next 14)
1238 20m38s test-tav (next 20)
1310 21m50s test-tav (next 16)

checklist

• wait for 4.1.0 release to go out
• add a changelog entry for this

[trentm]

cla/check

[trentm]

/test tav next

[trentm]

@elasticmachine, run elasticsearch-ci/docs