Compile integration tests before running them

[friedrichg]

What this PR does: Compile integration tests before running them

Checklist

• Tests updated
• Documentation added
• CHANGELOG.md updated - the order of entries should be [CHANGE], [FEATURE], [ENHANCEMENT], [BUGFIX]
• docs/configuration/v1-guarantees.md updated if this PR introduces experimental flags

Here are the per-job totals.

job                                                                       master        PR         Δ
--------------------------------------------------------------------------------------------------
build                                                                       274s      288s      +14s
build-integration-tests (amd64)                                                —      162s       new
build-integration-tests (arm64)                                                —      127s       new
integration (ubuntu-24.04, amd64, integration_alertmanager)                 291s      170s     -121s
integration (ubuntu-24.04, amd64, integration_backward_compatibility)       401s      291s     -110s
integration (ubuntu-24.04, amd64, integration_grpc)                         195s       73s     -122s
integration (ubuntu-24.04, amd64, integration_memberlist)                   621s      482s     -139s
integration (ubuntu-24.04, amd64, integration_overrides)                    139s       30s     -109s
integration (ubuntu-24.04, amd64, integration_querier)                      471s      337s     -134s
integration (ubuntu-24.04, amd64, integration_querier_microservices_mode)   717s      586s     -131s
integration (ubuntu-24.04, amd64, integration_query_fuzz)                   422s      288s     -134s
integration (ubuntu-24.04, amd64, integration_remote_write_v2)              200s       63s     -137s
integration (ubuntu-24.04, amd64, integration_ruler)                        389s      263s     -126s
integration (ubuntu-24.04, amd64, requires_docker)                          698s      447s     -251s
integration (ubuntu-24.04-arm, arm64, integration_alertmanager)             291s      191s     -100s
integration (ubuntu-24.04-arm, arm64, integration_backward_compatibility)   419s      314s     -105s
integration (ubuntu-24.04-arm, arm64, integration_grpc)                     186s       79s     -107s
integration (ubuntu-24.04-arm, arm64, integration_memberlist)               593s      537s      -56s
integration (ubuntu-24.04-arm, arm64, integration_overrides)                145s       54s      -91s
integration (ubuntu-24.04-arm, arm64, integration_querier)                  428s      304s     -124s
integration (ubuntu-24.04-arm, arm64, integration_querier_microservices_mode) 715s    613s     -102s
integration (ubuntu-24.04-arm, arm64, integration_query_fuzz)               395s      309s      -86s
integration (ubuntu-24.04-arm, arm64, integration_remote_write_v2)          196s       94s     -102s
integration (ubuntu-24.04-arm, arm64, integration_ruler)                    380s      300s      -80s
integration (ubuntu-24.04-arm, arm64, requires_docker)                      687s      463s     -224s
integration-configs-db (ubuntu-24.04, amd64)                                191s      172s      -19s
integration-configs-db (ubuntu-24.04-arm, arm64)                            175s      169s       -6s
lint                                                                        355s      347s       -8s
test (amd64)                                                                737s      726s      -11s
test (arm64)                                                                623s      603s      -20s
test-no-race (amd64)                                                        499s      530s      +31s
test-no-race (arm64)                                                        461s      485s      +24s

Savings range from ~56 s (smallest) to ~251 s (requires_docker) per integration entry. The new build-integration-tests job adds 162 s / 127 s but runs in parallel with build, so it stays off the critical path.

[friedrichg]

I thought about implementing integration-configs-db too. But we can leave that for the next PR