Update skylib to fix gazelle

[alexbozhenko]

Currently, running gazelle fails:

$ bazel run //:gazelle  -- -help
ERROR: Traceback (most recent call last):
        File "/home/alex/.cache/bazel/_bazel_alex/6ff60870017843370a59ce449c5a420a/external/bazel_gazelle/internal/BUILD.bazel", line 19, column 26, in <toplevel>
                gazelle_binary_test_suite()
        File "/home/alex/.cache/bazel/_bazel_alex/6ff60870017843370a59ce449c5a420a/external/bazel_gazelle/internal/gazelle_binary_test.bzl", line 27, column 19, in gazelle_binary_test_suite
                unittest.suite(
        File "/home/alex/.cache/bazel/_bazel_alex/6ff60870017843370a59ce449c5a420a/external/bazel_skylib/lib/unittest.bzl", line 269, column 18, in _suite
                test_rule(name = test_name)
Error: 'struct' object is not callable
ERROR: /home/alex/code/protoc-gen-validate/BUILD.bazel:9:8: every rule of type _gazelle_runner implicitly depends upon the target '@bazel_gazelle//internal:gazelle.bash.in', but this target could not be found because of: no such target '@bazel_gazelle//internal:gazelle.bash.in': target 'gazelle.bash.in' not declared in package 'internal' defined by /home/alex/.cache/bazel/_bazel_alex/6ff60870017843370a59ce449c5a420a/external/bazel_gazelle/internal/BUILD.bazel; however, a source file of this name exists.  (Perhaps add 'exports_files(["gazelle.bash.in"])' to internal/BUILD?)
ERROR: Analysis of target '//:gazelle' failed; build aborted: 
INFO: Elapsed time: 0.486s
INFO: 0 processes.
FAILED: Build did NOT complete successfully (7 packages loaded, 142 targets configured)
ERROR: Build failed. Not running target

Similar issue is described here: bazel-contrib/rules_go#3532 (comment)

After the update it works:

$ bazel run //:gazelle  -- -help
...
Gazelle is a BUILD file generator for Go projects. It can create new BUILD files
...

Update skylib to the latest version.
Also, use releases URL (https://blog.bazel.build/2023/02/15/github-archive-checksum.html)

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