pull agent image instead of rebuilding

[rochdev]

What does this PR do?

Pull agent image instead of rebuilding.

Motivation

The agent can only change in the system tests repo, so there is no reason to keep rebuilding it on every commit.

[github-actions]

Overall package size

Self size: 6.82 MB
Deduped: 58.31 MB
No deduping: 58.59 MB

Dependency sizes

name	version	self size	total size
@datadog/native-appsec	8.0.1	15.59 MB	15.6 MB
@datadog/native-iast-taint-tracking	3.0.0	11.14 MB	11.15 MB
@datadog/pprof	5.3.0	9.85 MB	10.22 MB
protobufjs	7.2.5	2.77 MB	6.56 MB
@datadog/native-iast-rewriter	2.3.1	2.15 MB	2.24 MB
@opentelemetry/core	1.14.0	872.87 kB	1.47 MB
@datadog/native-metrics	2.0.0	898.77 kB	1.3 MB
@opentelemetry/api	1.8.0	1.21 MB	1.21 MB
import-in-the-middle	1.8.1	71.67 kB	741.34 kB
msgpack-lite	0.1.26	201.16 kB	281.59 kB
opentracing	0.14.7	194.81 kB	194.81 kB
semver	7.5.4	93.4 kB	123.8 kB
pprof-format	2.1.0	111.69 kB	111.69 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
ignore	5.2.4	51.22 kB	51.22 kB
int64-buffer	0.1.10	49.18 kB	49.18 kB
shell-quote	1.8.1	44.96 kB	44.96 kB
istanbul-lib-coverage	3.2.0	29.34 kB	29.34 kB
tlhunter-sorted-set	0.1.0	24.94 kB	24.94 kB
limiter	1.1.5	23.17 kB	23.17 kB
dc-polyfill	0.1.4	23.1 kB	23.1 kB
retry	0.13.1	18.85 kB	18.85 kB
jest-docblock	29.7.0	8.99 kB	12.76 kB
crypto-randomuuid	1.0.0	11.18 kB	11.18 kB
path-to-regexp	0.1.7	6.78 kB	6.78 kB
koalas	1.0.2	6.47 kB	6.47 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}

[pr-commenter]

Benchmarks

Benchmark execution time: 2024-07-05 19:54:50

Comparing candidate commit c40480d in PR branch system-test-pull-agent with baseline commit 2d06797 in branch master.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 257 metrics, 9 unstable metrics.