chore(deps): Bump rdkafka from 0.38.0 to 0.39.0 (#24602)

* Update rdkafka to 0.39.0

* Update 3rd party license CSV

* Update licenses

* Add libsasl2 MacOS intructions

* Fix spellcheck

* Fix markdown

* Improve docs

---------

Co-authored-by: Thomas <thomas.schneider@datadoghq.com>
Co-authored-by: Pavlos Rontidis <pavlos.rontidis@gmail.com>

Author: 3 people

.github/actions/spelling/allow.txt

@@ -562,6 +562,10 @@ zstandard
 ZTE
 Zync
 sighup
+CPPFLAGS
+LDFLAGS
+libsasl
+pkgconfig
 CLAUDE
 linting
 lexers

Cargo.lock

@@ -419,7 +419,7 @@ pulsar = { version = "6.7.0", default-features = false, features = ["tokio-runti
 quick-junit = { version = "0.5.1" }
 rand.workspace = true
 rand_distr.workspace = true
-rdkafka = { version = "0.38.0", default-features = false, features = ["curl-static", "tokio", "libz", "ssl", "zstd"], optional = true }
+rdkafka = { version = "0.39.0", default-features = false, features = ["curl-static", "tokio", "libz", "ssl", "zstd"], optional = true }
 redis = { version = "0.32.4", default-features = false, features = ["connection-manager", "sentinel", "tokio-comp", "tokio-native-tls-comp"], optional = true }
 regex.workspace = true
 roaring = { version = "0.11.2", default-features = false, features = ["std"], optional = true }

Cargo.toml

@@ -123,6 +123,19 @@ To build Vector on your own host will require a fairly complete development envi
 Loosely, you'll need the following:
 
 - **To build Vector:** Have working Rustup, Protobuf tools, C++/C build tools (LLVM, GCC, or MSVC), Python, and Perl, `make` (the GNU one preferably), `bash`, `cmake`, `GNU coreutils`, and `autotools`.
+  - You may also need to install `libsasl2` if you are compiling with default features or with any `kafka`-related features.
+    - Installing libsasl2 on Ubuntu
+      - Run `sudo apt-get install -y libsasl2-dev`
+    - Installing libsasl2 on MacOS
+      - Run `brew install cyrus-sasl`
+      - You will need to set the following environment variables:
+
+        ```bash
+        export LDFLAGS="-L$(brew --prefix cyrus-sasl)/lib $LDFLAGS"
+        export CPPFLAGS="-I$(brew --prefix cyrus-sasl)/include $CPPFLAGS"
+        export PKG_CONFIG_PATH="$(brew --prefix cyrus-sasl)/lib/pkgconfig:$PKG_CONFIG_PATH"
+        ```
+
 - **To run `make test`:** Install [`cargo-nextest`](https://nexte.st/)
 - **To run integration tests:** Have `docker` available, or a real live version of that service. (Use `AUTOSPAWN=false`)
 - **To run `make check-component-features`:** Have `remarshal` installed.