Fix indexing, upgrade MeiliSearch sdk (#100)

* Hotfixes for indexing

* Handles missing INDEX_CACHE_PATH environment variable
* Exits on startup if environment variables are missing. The flag
  --allow-missing-vars disables this, but that is generally a bad
  idea, since most environment variables are required (and the ones
  that aren't should be marked as such).
* Disables the query loggers

* Upgrade meilisearch-sdk to 0.4.0 for MeiliSearch 0.16 support

* Fix swap of Forge and Fabric labeling

Cargo.lock

@@ -1726,15 +1726,14 @@ checksum = "490cc448043f947bae3cbee9c203358d62dbee0db12107a74be5c30ccfd09771"
 
 [[package]]
 name = "meilisearch-sdk"
-version = "0.3.0"
+version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3a9e61da1ebd3d15e0aaa978d3f1f080e3793494ddea0bc6703da4b330ea1ffc"
+checksum = "cb2081610089deb10290747b8782049f9cb64a70a4d305a28970db8b780d1448"
 dependencies = [
  "log",
  "reqwest",
  "serde",
  "serde_json",
- "urlencoding",
  "wasm-bindgen",
  "wasm-bindgen-futures",
  "web-sys",
@@ -3009,12 +3008,6 @@ dependencies = [
  "percent-encoding",
 ]
 
-[[package]]
-name = "urlencoding"
-version = "1.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c9232eb53352b4442e40d7900465dfc534e8cb2dc8f18656fcb2ac16112b5593"
-
 [[package]]
 name = "v_escape"
 version = "0.13.2"