Switch to fork of thanos-io/objstore with fix for Exists() calls against GCS (#11546)

Author: charleskorn

go.mod

@@ -360,3 +360,6 @@ replace github.com/prometheus/alertmanager => github.com/grafana/prometheus-aler
 // Use Mimir fork of prometheus/otlptranslator to allow for higher velocity of upstream development,
 // while allowing Mimir to move at a more conservative pace.
 replace github.com/prometheus/otlptranslator => github.com/grafana/mimir-otlptranslator v0.0.0-20250501145537-53ceaec28820
+
+// Replace objstore with a fork containing https://github.com/thanos-io/objstore/pull/181.
+replace github.com/thanos-io/objstore => github.com/charleskorn/objstore v0.0.0-20250527015333-2865768f74cc

go.sum

@@ -214,6 +214,8 @@ github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UF
 github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/charleskorn/go-grpc v0.0.0-20231024023642-e9298576254f h1:P1GSPnbxmhUafKGBcaY2qqx34mBdC4GVDm/RN3iKKuE=
 github.com/charleskorn/go-grpc v0.0.0-20231024023642-e9298576254f/go.mod h1:DYR5Eij8rJl8h7gblRrOZ8g0kW1umSpKqYIBTgeDtLo=
+github.com/charleskorn/objstore v0.0.0-20250527015333-2865768f74cc h1:mYczEn9/UiMqwEvgRm9PuvBb1OGFpPyLLKaNKk4IB/Y=
+github.com/charleskorn/objstore v0.0.0-20250527015333-2865768f74cc/go.mod h1:Nmy3+M2UM7wu2sEvg0h5M/c3mu1QaxmdyPvoGUPGlaU=
 github.com/chromedp/cdproto v0.0.0-20210526005521-9e51b9051fd0/go.mod h1:At5TxYYdxkbQL0TSefRjhLE3Q0lgvqKKMSFUglJ7i1U=
 github.com/chromedp/cdproto v0.0.0-20210706234513-2bc298e8be7f/go.mod h1:At5TxYYdxkbQL0TSefRjhLE3Q0lgvqKKMSFUglJ7i1U=
 github.com/chromedp/cdproto v0.0.0-20230802225258-3cf4e6d46a89 h1:aPflPkRFkVwbW6dmcVqfgwp1i+UWGFH6VgR1Jim5Ygc=
@@ -1010,8 +1012,6 @@ github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf
 github.com/subosito/gotenv v1.4.1/go.mod h1:ayKnFf/c6rvx/2iiLrJUk1e6plDbT3edrFNGqEflhK0=
 github.com/tencentyun/cos-go-sdk-v5 v0.7.40 h1:W6vDGKCHe4wBACI1d2UgE6+50sJFhRWU4O8IB2ozzxM=
 github.com/tencentyun/cos-go-sdk-v5 v0.7.40/go.mod h1:4dCEtLHGh8QPxHEkgq+nFaky7yZxQuYwgSJM87icDaw=
-github.com/thanos-io/objstore v0.0.0-20250317105316-a0136a6f898d h1:L4k+8i1cl0h3MscslVUAcBpvA5i9UYzE0DybcOxzvlM=
-github.com/thanos-io/objstore v0.0.0-20250317105316-a0136a6f898d/go.mod h1:Nmy3+M2UM7wu2sEvg0h5M/c3mu1QaxmdyPvoGUPGlaU=
 github.com/tinylib/msgp v1.1.8/go.mod h1:qkpG+2ldGg4xRFmx+jfTvZPxfGFhi64BcnL9vkCm/Tw=
 github.com/tjhop/slog-gokit v0.1.4 h1:uj/vbDt3HaF0Py8bHPV4ti/s0utnO0miRbO277FLBKM=
 github.com/tjhop/slog-gokit v0.1.4/go.mod h1:Bbu5v2748qpAWH7k6gse/kw3076IJf6owJmh7yArmJs=