chore: Update from rc release of LLVM and llvm-sys to the stable one

- Update `llvm-sys` from `191.0.0-rc1` to `191.0.0`.
- Update LLVM to the `rustc/19.1-2024-09-17` branch, which is based
  on the stable LLVM 19.1.0 release.
  - The mentioned branch in our LLVM fork contains a backport of
    llvm/llvm-project#107802, which is needed for our work on BTF
    relocations.

.github/workflows/llvm.yml

@@ -16,7 +16,7 @@ jobs:
       - id: ls-remote
         run: |
           set -euxo pipefail
-          value=$(git ls-remote https://github.com/aya-rs/llvm-project.git refs/heads/rustc/19.1-2024-07-30 | cut -f1)
+          value=$(git ls-remote https://github.com/aya-rs/llvm-project.git refs/heads/rustc/19.1-2024-09-17 | cut -f1)
           echo "sha=$value" >> "$GITHUB_OUTPUT"
 
       - id: cache-key

Cargo.toml

@@ -28,7 +28,7 @@ ar = { version = "0.9.0" }
 aya-rustc-llvm-proxy = { version = "0.9.3", optional = true }
 gimli = { version = "0.31.0" }
 libc = { version = "0.2.158" }
-llvm-sys = { features = ["disable-alltargets-init"], version = "191.0.0-rc1" }
+llvm-sys = { features = ["disable-alltargets-init"], version = "191.0.0" }
 log = { version = "0.4.22" }
 thiserror = { version = "1.0.64" }
 tracing = "0.1"