fix(bazel): Always disable the disk cache

When the disk-cache is set via `.bazelrc` to a non-existing directory,
`bazel mod graph` fails with a complaint about permissions, which in
turn makes the analysis fail.

The disk cache is a build cache which seems to target speeding up
builds in case of code changes (such as switching branches) [1]. During
ORT analysis code changes are not in play, so the disk cache seems to
be of little use anyway. Simply disable it to avoid running into that
permission issue.

Fixes: #8802.

[1] https://stackoverflow.com/questions/61282419/bazel-how-outputroot-and-disk-cache-relate-regarding-local-caching

Signed-off-by: Frank Viernau <[email protected]>

plugins/package-managers/bazel/src/funTest/assets/projects/synthetic/bazel/.bazelrc

@@ -0,0 +1 @@
+common --disk_cache=/non-existing-dir

plugins/package-managers/bazel/src/main/kotlin/Bazel.kt

@@ -169,7 +169,10 @@ class Bazel(
         }.getOrNull()
 
     private fun getDependencyGraph(projectDir: File, depDirectives: Map<String, BazelDepDirective>): Set<Scope> {
-        val modGraphProcess = run("mod", "graph", "--output", "json", workingDir = projectDir)
+        val modGraphProcess = run(
+            "mod", "graph", "--output", "json", "--disk_cache=", workingDir = projectDir
+        )
+
         val node = JSON.decodeFromString<ModuleGraphNode>(modGraphProcess.stdout)
         val devDeps = node.dependencies.filter { depDirectives[it.key]?.devDependency == true }.toSet()
         val mainDeps = node.dependencies.toSet() - devDeps