Merge #4304

4304: Add CUDA GPU support for Hugging Face embedders r=Kerollmops a=dureuill

Adds a "cuda" feature to `milli`.

Compiling with this feature requires that the CUDA support library be installed (see "with CUDA support" paragraph in https://huggingface.github.io/candle/guide/installation.html), and adds CUDA support to the `huggingFace` embedder.

To enable GPU support, users will need to:

1. Have a compatible NVidia GPU under Linux
2. Follow [the guide](https://huggingface.github.io/candle/guide/installation.html) to install the CUDA dependencies
3. Compile Meilisearch with the `cuda` feature: `cargo build --release --features cuda`

# Impact

Enabling the CUDA feature allows to use an available GPU to compute embeddings with a `huggingFace` embedder. 
On an AWS Graviton 2, this yields a x3 - x5 improvement on indexing time.

# Technical details

- I had to change the CI so that the cuda feature is not included in the `Tests all features` workflow
- To achieve that, I had to add a binary following the `cargo xtask` design pattern, to list all features excepted the cuda one.
- I then changed the workflow accordingly (renamed to "Tests almost all features" 😉)
- A test run of the new feature was done on a temporary version of this PR that had it enabled for PRs: [See the results here](https://github.com/meilisearch/meilisearch/actions/runs/7461331929/job/20301216732)

Co-authored-by: Louis Dureuil <louis@meilisearch.com>

Cargo.lock

@@ -700,12 +700,23 @@ dependencies = [
  "displaydoc",
 ]
 
+[[package]]
+name = "camino"
+version = "1.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c59e92b5a388f549b863a7bea62612c09f24c8393560709a54558a9abdfb3b9c"
+dependencies = [
+ "serde",
+]
+
 [[package]]
 name = "candle-core"
 version = "0.3.3"
 source = "git+https://github.com/huggingface/candle.git#5270224f407502b82fe90bc2622894ce3871b002"
 dependencies = [
  "byteorder",
+ "candle-kernels",
+ "cudarc",
  "gemm",
  "half 2.3.1",
  "memmap2 0.9.3",
@@ -720,6 +731,16 @@ dependencies = [
  "zip",
 ]
 
+[[package]]
+name = "candle-kernels"
+version = "0.3.1"
+source = "git+https://github.com/huggingface/candle.git#f4fcf6090045ac44122fd5f0a7e46db6e3e16528"
+dependencies = [
+ "anyhow",
+ "glob",
+ "rayon",
+]
+
 [[package]]
 name = "candle-nn"
 version = "0.3.3"
@@ -752,6 +773,29 @@ dependencies = [
  "wav",
 ]
 
+[[package]]
+name = "cargo-platform"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ceed8ef69d8518a5dda55c07425450b58a4e1946f4951eab6d7191ee86c2443d"
+dependencies = [
+ "serde",
+]
+
+[[package]]
+name = "cargo_metadata"
+version = "0.18.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2d886547e41f740c616ae73108f6eb70afe6d940c7bc697cb30f13daec073037"
+dependencies = [
+ "camino",
+ "cargo-platform",
+ "semver",
+ "serde",
+ "serde_json",
+ "thiserror",
+]
+
 [[package]]
 name = "cargo_toml"
 version = "0.18.0"
@@ -1163,6 +1207,15 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "cudarc"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9395df0cab995685664e79cc35ad6302bf08fb9c5d82301875a183affe1278b1"
+dependencies = [
+ "half 2.3.1",
+]
+
 [[package]]
 name = "darling"
 version = "0.14.4"
@@ -4827,6 +4880,9 @@ name = "semver"
 version = "1.0.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b0293b4b29daaf487284529cc2f5675b8e57c61f70167ba415a463651fd6a918"
+dependencies = [
+ "serde",
+]
 
 [[package]]
 name = "seq-macro"
@@ -6174,6 +6230,14 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "xtask"
+version = "1.6.0"
+dependencies = [
+ "cargo_metadata",
+ "clap",
+]
+
 [[package]]
 name = "yada"
 version = "0.5.0"