fix: optimize packages upload memory (#39366)

Bound the memory used when parsing uploaded packages, so instances with
low memory limits survive non-standard packages.

1. Metadata files are read through a size-limited reader, archives
themselves stay unbounded so large payloads keep working
2. zstd decoding caps the window at 128 MiB, the zstd CLI default
3. RPM headers go through a first-party reader with rpmlib's size and
array count limits that allocates only what the upload contains, until
https://github.com/sassoftware/go-rpmutils/pull/44 is released. Signing
still verifies the payload digest, and its signature header matches
rpmsign's byte for byte
4. Swift and NuGet read the zip entry they size-checked, a duplicate
name could stand in for it before
5. Terraform states check `LIMIT_SIZE_TERRAFORM_STATE` before parsing,
NuGet symbol PDBs share a 256 MiB budget
6. Oversized container configs are rejected instead of stored without
metadata, invalid Vagrant boxes answer 400 instead of 500

Signed-off-by: techknowlogick <git@tklk.dev>
Co-authored-by: techknowlogick <git@tklk.dev>
Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: techknowlogick <techknowlogick@gitea.com>

modules/packages/cargo/parser.go

@@ -10,6 +10,7 @@ import (
 	"regexp"
 
 	"gitea.dev/modules/json"
+	"gitea.dev/modules/packages"
 	"gitea.dev/modules/validation"
 
 	"github.com/hashicorp/go-version"
@@ -67,6 +68,9 @@ func ParsePackage(r io.Reader) (*Package, error) {
 	if err := binary.Read(r, binary.LittleEndian, &size); err != nil {
 		return nil, err
 	}
+	if size > packages.MaxMetadataSize {
+		return nil, packages.ErrContentTooLarge
+	}
 
 	p, err := parsePackage(io.LimitReader(r, int64(size)))
 	if err != nil {