[7.2.0] Do not delay `TargetCompleteEvents` with coverage

[bazel-io]

Baseline coverage artifacts are now requested in CompletionFunction to ensure that they are built before the TargetCompleteEvent is generated. This makes it unnecessary to delay sending these events until after a Skymeld build has had the chance to request all coverage artifacts directly, which could only be done after the analysis & execution phase, thus delaying events until the end of the build.

Fixes #21475

Closes #22238.

PiperOrigin-RevId: 631414420 Change-Id: Idc77b6f5c8b5b775e6c69e35c5563f63b3bf974f

Commit https://github.com/bazelbuild/bazel/commit/fd2cc92ad7aa27878645b15c52474c9019233de9