Update heroku/buildpacks-python to v0.13.0 (#559)

## heroku/python

### Changed

- Stopped manually creating a `src` directory inside the Pip dependencies layer. Pip will create the directory itself if needed (when there are editable VCS dependencies). ([#228](heroku/buildpacks-python#228))
- Stopped setting `CPATH` and `PKG_CONFIG_PATH` at launch time. ([#231](heroku/buildpacks-python#231))
- The `bin` directory in the Pip dependencies layer is now always added to `PATH` instead of only when an installed dependency has an entry point script. ([#232](heroku/buildpacks-python#232))
- The Pip cache layer is now exposed to Pip invocations in later buildpacks. ([#234](heroku/buildpacks-python#234))

Co-authored-by: heroku-linguist[bot] <136119646+heroku-linguist[bot]@users.noreply.github.com>

builder-20/builder.toml

@@ -34,7 +34,7 @@ version = "0.20.0"
 
 [[buildpacks]]
   id = "heroku/python"
-  uri = "docker://docker.io/heroku/buildpack-python@sha256:77fe665f56528d9a259ca7e5b9338f32fe41811d20680fe0c17e33d071dec2a8"
+  uri = "docker://docker.io/heroku/buildpack-python@sha256:d87aae7fb38ff279b1b1861d6eaf62053c11131576898e36d18e97bc0c6c95ec"
 
 [[buildpacks]]
   id = "heroku/ruby"
@@ -47,7 +47,7 @@ version = "0.20.0"
 [[order]]
   [[order.group]]
     id = "heroku/python"
-    version = "0.12.1"
+    version = "0.13.0"
   [[order.group]]
     id = "heroku/procfile"
     version = "3.1.2"

builder-22/builder.toml

@@ -30,7 +30,7 @@ version = "0.20.0"
 
 [[buildpacks]]
   id = "heroku/python"
-  uri = "docker://docker.io/heroku/buildpack-python@sha256:77fe665f56528d9a259ca7e5b9338f32fe41811d20680fe0c17e33d071dec2a8"
+  uri = "docker://docker.io/heroku/buildpack-python@sha256:d87aae7fb38ff279b1b1861d6eaf62053c11131576898e36d18e97bc0c6c95ec"
 
 [[buildpacks]]
   id = "heroku/ruby"
@@ -43,7 +43,7 @@ version = "0.20.0"
 [[order]]
   [[order.group]]
     id = "heroku/python"
-    version = "0.12.1"
+    version = "0.13.0"
   [[order.group]]
     id = "heroku/procfile"
     version = "3.1.2"

builder-24/builder.toml

@@ -30,7 +30,7 @@ version = "0.20.0"
 
 [[buildpacks]]
   id = "heroku/python"
-  uri = "docker://docker.io/heroku/buildpack-python@sha256:77fe665f56528d9a259ca7e5b9338f32fe41811d20680fe0c17e33d071dec2a8"
+  uri = "docker://docker.io/heroku/buildpack-python@sha256:d87aae7fb38ff279b1b1861d6eaf62053c11131576898e36d18e97bc0c6c95ec"
 
 [[buildpacks]]
   id = "heroku/ruby"
@@ -43,7 +43,7 @@ version = "0.20.0"
 [[order]]
   [[order.group]]
     id = "heroku/python"
-    version = "0.12.1"
+    version = "0.13.0"
   [[order.group]]
     id = "heroku/procfile"
     version = "3.1.2"