internal/pkg: compute http identifier from url

The previous implementation exposes arbitrary user input to the cache as an identifier, which is highly error-prone and can cause the cache to enter an inconsistent state if the user is not careful. This change replaces the implementation to compute identifier late, using url string as params.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/pkg/tar.go

@@ -43,12 +43,8 @@ func NewHTTPGetTar(
 	url string,
 	checksum Checksum,
 	compression uint64,
-) (Artifact, error) {
-	f, err := NewHTTPGet(ctx, hc, url, checksum)
-	if err != nil {
-		return nil, err
-	}
-	return NewTar(f, compression), nil
+) Artifact {
+	return NewTar(NewHTTPGet(ctx, hc, url, checksum), compression)
 }
 
 // Kind returns the hardcoded [Kind] constant.