CI: Make validate-spaces quick

[trianglesphere]

Description

By attaching the outputs from the monorepo build step at the right place, we don't need to rebuild contracts for the validate-spaces test.

[codecov]

Codecov Report

Merging #8121 (09bfc79) into develop (3b28485) will increase coverage by 0.24%.
Report is 10 commits behind head on develop.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           develop    #8121      +/-   ##
===========================================
+ Coverage    53.58%   53.83%   +0.24%     
===========================================
  Files          162      162              
  Lines         6171     6171              
  Branches       966      966              
===========================================
+ Hits          3307     3322      +15     
+ Misses        2735     2723      -12     
+ Partials       129      126       -3     

Flag	Coverage Δ
cannon-go-tests	63.47% <ø> (ø)
chain-mon-tests	26.95% <ø> (ø)
common-ts-tests	26.74% <ø> (ø)
contracts-bedrock-tests	61.89% <ø> (+0.76%)	⬆️
contracts-ts-tests	100.00% <ø> (ø)
core-utils-tests	44.03% <ø> (ø)
sdk-next-tests	41.92% <ø> (ø)
sdk-tests	41.92% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

see 6 files with indirect coverage changes

[ajsutton]

Validate spaces failed in the merge queue - may just be flaky but the error suggested node_modules wasn't present:

Ran 174 test suites: 820 tests passed, 2 failed, 0 skipped (822 total tests)

Failing tests:
Encountered 1 failing test in test/BenchmarkTest.t.sol:SetPrevBaseFee_Test
[FAIL. Reason: Setup failed: Misconfigured networks:  != 31337] setUp() (gas: 0)

Encountered 1 failing test in test/Hashing.t.sol:Hashing_hashOutputRootProof_Test
[FAIL. Reason: Setup failed: Misconfigured networks:  != 31337] setUp() (gas: 0)

Encountered a total of 2 failing tests, 820 tests succeeded
 ELIFECYCLE  Test failed. See above for more details.
 WARN   Local package.json exists, but node_modules missing, did you mean to install?