images module extension: allow downloading blobs from multiple sources

[malt3]

No description provided.

[aspect-workflows]

Bazel 8 (Test)

3 test targets passed

Targets

//img/private/release/gazelle_plugin:release_files_test [k8-fastbuild]                 247ms
//tests/img_toolchain:img_toolchain_test [k8-fastbuild]                                458ms
//util:buildifier.check [k8-fastbuild]                                                 2s

Total test execution time was 3s. 17 tests (85.0%) were fully cached saving 11s.

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Integration Tests (Test)

17 test targets passed

Targets

//e2e:cc_bazel_7_4_0         4m 51s
//e2e:cc_bazel_8_4_2         4m 50s
//e2e:cc_bazel_9_0_0rc1      4m 59s
//e2e:generic_bazel_7_4_0    2m 20s
//e2e:generic_bazel_8_4_2    1m 59s
//e2e:generic_bazel_9_0_0rc1 1m 58s
//e2e:go_bazel_7_4_0         5m 27s
//e2e:go_bazel_8_4_2         5m 26s
//e2e:go_bazel_9_0_0rc1      5m 24s
//e2e:js_bazel_7_4_0         40s
//e2e:js_bazel_8_4_2         39s
//e2e:js_bazel_9_0_0rc1      40s
//e2e:python_bazel_7_4_0     1m 49s
//e2e:python_bazel_8_4_2     1m 44s
//e2e:python_bazel_9_0_0rc1  1m 47s
//e2e:workspace_bazel_7_4_0  16s
//e2e:workspace_bazel_8_4_2  19s

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Buildifier