Make lockfile's RepoSpec attributes more readable

[fmeum]

String-valued tag and repo rule attributes in the MODULE.bazel.lock file have to be serialized in a way that distinguishes them from label-valued attributes. This commit uses the fact that the string representation of labels always starts with @@ to escape strings only if they start with @@ (or happen to be of the form of an escaped string). Since string-valued attributes rarely start with @@, in particular when specified by humans and not macros, this greatly reduces the need for escaping in the lockfile.

This commit raises the lockfile version to 3.

Along the way also disables HTML escaping for attributes as it isn't needed and results in less readable representations of certain characters.

[meteorcloudy]

To fix the bootstrap and determinism tests, you'll have to update the hack at:
https://cs.opensource.google/search?q=%22lockFileVersion%5C%22:%201%2F%5C%22lockFileVersion%5C%22:%202%2F%22&sq=&ss=bazel

[fmeum]

@bazel-io flag

[iancha1992]

@bazel-io fork 6.4.0

[iancha1992]

@meteorcloudy @Wyverald @SalmaSamy @fmeum There are some conflicts when I try to cherry-pick this to release-6.4.0

1. scripts/bootstrap/compile.sh

link_file "${PWD}/src/MODULE.tools" "${BAZEL_TOOLS_REPO}/MODULE.bazel"
new_hash=$(shasum -a 256 "${BAZEL_TOOLS_REPO}/MODULE.bazel" | awk '{print $1}')
sed -i.bak "/\"bazel_tools\":/s/\"[a-f0-9]*\"/\"$new_hash\"/" MODULE.bazel.lock

is not in the release-6.4.0 branch. But it's in the master branch.

2. src/test/shell/bazel/bazel_determinism_test.sh

# Set up the maven repository properly.
cp derived/maven/BUILD.vendor derived/maven/BUILD
# Update the hash of bazel_tools in lockfile to avoid rerunning module resolution.
new_hash=$(shasum -a 256 "src/MODULE.tools" | awk '{print $1}')
sed -i.bak "/\"bazel_tools\":/s/\"[a-f0-9]*\"/\"$new_hash\"/" MODULE.bazel.lock
# TODO: Temporary hack for lockfile version mismatch, remove these two lines after updating to 6.4.0

is not in the release-6.4.0 branch. But it's in the master branch.

3. src/tools/bzlmod/utils.bzl does not exist in the releae-6.4.0 branch at all currently

cc: @bazelbuild/triage

[fmeum]

@meteorcloudy Could you resolve these conflicts? I'm not sure I understand which branch needs which version of this workaround.

[meteorcloudy]

Np, I can do it!

[meteorcloudy]

We just need to drop all three conflict changes: #19748

[iancha1992]

The changes in this PR have been included in Bazel 6.4.0 RC2. Please test out the release candidate and report any issues as soon as possible. If you're using Bazelisk, you can point to the latest RC by setting USE_BAZEL_VERSION=last_rc.
Thanks!