Update libcnb from 0.14.0 to 0.15.0

This also required updating `toml` to 0.8 to prevent a type mismatch
error due to the `jvm-function-invoker` buildpack using
`libherokubuildpack::toml::toml_select_value` (which itself  is now using
toml 0.8).

https://github.com/heroku/libcnb.rs/releases/tag/v0.15.0
heroku/libcnb.rs@v0.14.0...v0.15.0

GUS-W-14354898.

Cargo.toml

@@ -20,9 +20,9 @@ publish = false
 [workspace.dependencies]
 # libcnb has a much bigger impact on buildpack behaviour than any other dependencies,
 # so it's pinned to an exact version to isolate it from lockfile refreshes.
-libcnb = "=0.14.0"
-libcnb-test = "=0.14.0"
-libherokubuildpack = "=0.14.0"
-toml = "0.7"
+libcnb = "=0.15.0"
+libcnb-test = "=0.15.0"
+libherokubuildpack = "=0.15.0"
+toml = "0.8"
 buildpacks-jvm-shared = { path = "shared" }
 buildpacks-jvm-shared-test = { path = "shared-test" }

buildpacks/gradle/tests/integration/main.rs

@@ -13,7 +13,7 @@ mod ux;
 pub(crate) fn default_buildpacks() -> Vec<BuildpackReference> {
     vec![
         BuildpackReference::Other(String::from("heroku/jvm")),
-        BuildpackReference::Crate,
+        BuildpackReference::CurrentCrate,
         // Using an explicit version from Docker Hub to prevent failures when there
         // are multiple Procfile buildpack versions in the builder image.
         BuildpackReference::Other(String::from("docker://docker.io/heroku/procfile-cnb:2.0.1")),

buildpacks/jvm-function-invoker/tests/integration/smoke.rs

@@ -13,7 +13,7 @@ fn smoke_test_simple_function() {
         BuildConfig::new(DEFAULT_INTEGRATION_TEST_BUILDER, "test-apps/simple-function").buildpacks([
             BuildpackReference::Other(String::from("heroku/jvm")),
             BuildpackReference::Other(String::from("heroku/maven")),
-            BuildpackReference::Crate,
+            BuildpackReference::CurrentCrate,
         ]),
         |context| {
             context.start_container(

buildpacks/maven/tests/integration/main.rs

@@ -29,6 +29,6 @@ pub(crate) fn default_config() -> BuildConfig {
 pub(crate) fn default_buildpacks() -> Vec<BuildpackReference> {
     vec![
         BuildpackReference::Other(String::from("heroku/jvm")),
-        BuildpackReference::Crate,
+        BuildpackReference::CurrentCrate,
     ]
 }

buildpacks/sbt/tests/integration/main.rs

@@ -15,7 +15,7 @@ mod ux;
 pub(crate) fn default_buildpacks() -> Vec<BuildpackReference> {
     vec![
         BuildpackReference::Other(String::from("heroku/jvm")),
-        BuildpackReference::Crate,
+        BuildpackReference::CurrentCrate,
         // Using an explicit version from Docker Hub to prevent failures when there
         // are multiple Procfile buildpack versions in the builder image.
         BuildpackReference::Other(String::from("docker://docker.io/heroku/procfile-cnb:2.0.1")),