fix requests to agent via IPv6

[tlhunter]

What does this PR do?

• testing IPv6 support for agent host
• ultimately the issue is that the request options hostname is set to [::1] instead of ::1
• see Support IPv6 URLs for agent address #2691, fix configuring an ipv6 agent hostname #2486
• DD_AGENT_HOST is not used properly when ipv6 address #2449 (comment)

Motivation

• a user is having issues when connecting to a datadog agent via IPv6 on a kubernetes cluster

> void http.request({url: 'http://[::1]:31921', hostname: '::1'})
  .on('error', (e) => console.log(e.code === 'ECONNREFUSED' ? 'good' : 'bad'))
undefined
> good
> void http.request({url: 'http://[::1]:31921', hostname: '[::1]'})
  .on('error', (e) => console.log(e.code === 'ECONNREFUSED' ? 'good' : 'bad'))
undefined
> bad

[github-actions]

Overall package size

Self size: 4.03 MB
Deduped: 59.68 MB
No deduping: 59.72 MB

Dependency sizes

name	version	self size	total size
@datadog/native-iast-taint-tracking	1.3.1	13.47 MB	13.47 MB
@datadog/pprof	2.1.0	12.31 MB	13.2 MB
@datadog/native-appsec	2.0.0	12.33 MB	12.34 MB
@datadog/native-metrics	1.5.0	7.1 MB	7.11 MB
protobufjs	7.1.2	2.76 MB	6.55 MB
@datadog/native-iast-rewriter	2.0.1	2.09 MB	2.1 MB
opentracing	0.14.7	194.81 kB	194.81 kB
semver	7.3.8	88.2 kB	118.6 kB
@datadog/sketches-js	2.1.0	109.9 kB	109.9 kB
lodash.sortby	4.7.0	75.76 kB	75.76 kB
lru-cache	7.14.0	74.95 kB	74.95 kB
ipaddr.js	2.0.1	59.52 kB	59.52 kB
ignore	5.2.0	48.87 kB	48.87 kB
import-in-the-middle	1.3.4	32.7 kB	37.17 kB
istanbul-lib-coverage	3.2.0	29.34 kB	29.34 kB
retry	0.10.1	27.44 kB	27.44 kB
lodash.uniq	4.5.0	25.01 kB	25.01 kB
limiter	1.1.5	23.17 kB	23.17 kB
lodash.kebabcase	4.1.1	17.75 kB	17.75 kB
lodash.pick	4.4.0	16.33 kB	16.33 kB
node-abort-controller	3.0.1	14.33 kB	14.33 kB
crypto-randomuuid	1.0.0	11.18 kB	11.18 kB
diagnostics_channel	1.1.0	7.07 kB	7.07 kB
path-to-regexp	0.1.7	6.78 kB	6.78 kB
koalas	1.0.2	6.47 kB	6.47 kB
methods	1.1.2	5.29 kB	5.29 kB
module-details-from-path	1.0.3	4.47 kB	4.47 kB

_{🤖 This report was automatically generated by heaviest-objects-in-the-universe}

[codecov]

Codecov Report

Merging #3003 (2f42b74) into master (0da8386) will increase coverage by 0.05%.
The diff coverage is 100.00%.

❗ Current head 2f42b74 differs from pull request most recent head 9e756be. Consider uploading reports for the commit 9e756be to get more accurate results

@@            Coverage Diff             @@
##           master    #3003      +/-   ##
==========================================
+ Coverage   87.63%   87.69%   +0.05%     
==========================================
  Files         329      329              
  Lines       11750    11749       -1     
  Branches       33       33              
==========================================
+ Hits        10297    10303       +6     
+ Misses       1453     1446       -7     

Impacted Files	Coverage Δ
packages/dd-trace/src/exporters/common/request.js	96.15% <100.00%> (+7.69%)	⬆️

... and 1 file with indirect coverage changes

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[pr-commenter]

Benchmarks

Comparing candidate commit 9e756be in PR branch tlhunter/ipv6-agent with baseline commit 0da8386 in branch master.

Found 0 performance improvements and 1 performance regressions! Performance is the same for 672 metrics, 35 unstable metrics.

scenario:plugin-graphql-control-14

• 🟥 execution_time [+0.426s; +0.563s] or [+16.396%; +21.681%]

[rochdev]

Not sure I understand what this does. Was it supposed to be a draft?