fix: Mark toolchain as reproducible

[mortenmj]

This allows the content produced by the repo rule to be fetched from the remote repo contents cache.

[aspect-workflows]

Bazel 7 (Test)

1 test target passed

Targets

//jq/tests:check_stamped [k8-fastbuild] 58ms

Total test execution time was 58ms. 11 tests (91.7%) were fully cached saving 625ms.

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Bazel 8 (Test)

1 test target passed

Targets

//jq/tests:check_stamped [k8-fastbuild] 126ms

Total test execution time was 126ms. 11 tests (91.7%) were fully cached saving 607ms.

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Bazel 9 (Test)

1 test target passed

Targets

//jq/tests:check_stamped [k8-fastbuild] 161ms

Total test execution time was 161ms. 11 tests (91.7%) were fully cached saving 593ms.

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Bazel 7 (Test)

e2e/smoke

All tests were cache hits

2 tests (100.0%) were fully cached saving 95ms.

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Bazel 8 (Test)

e2e/smoke

All tests were cache hits

2 tests (100.0%) were fully cached saving 114ms.

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Bazel 9 (Test)

e2e/smoke

All tests were cache hits

2 tests (100.0%) were fully cached saving 117ms.