fix: permit more label syntax when pre-computing outputs

[alexeagle]

fixes #584

[aspect-workflows]

Test

1 test target was executed and passed with no errors or flakes 🙌

Targets

//examples/srcs:test_generated [k8-fastbuild] 37ms

Total test execution time was 37ms. 63 tests (98.4%) were fully cached saving 6s.

---

Buildifier

Buildifier managed files require formatting

--- ./examples/srcs/BUILD.bazel	2024-04-11 21:37:55.687586677 +0000
+++ /tmp/buildifier-tmp-1219055211	2024-04-11 21:38:53.088045785 +0000
@@ -42,9 +42,9 @@
     # Demonstrates that you can mix sources with generated files
     # (Also verifies that relative labels work with macro logic for predeclared outputs)
     srcs = [
-        "//examples/srcs:a.ts",
         ":b.ts",
         ":generated.ts",
+        "//examples/srcs:a.ts",
     ],
     out_dir = "generated",
 )

💡 Run the following to apply the suggested formatting fixes

bazel run //:buildifier

---

Format

Formatting check has failed

💡 Some formatting failures can be fixed automatically by running the command below, while others may require manual fixes

bazel run //:format -- examples/srcs/BUILD.bazel

ℹ️ A patch file containing the changes has been archived as an artifact of this build

[jbedard]

Done in #571