deps: update alpine docker tag to v3.20 (#434)

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This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| alpine | final | minor | `3.15` -> `3.20` |

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Dockerfile

@@ -1,4 +1,4 @@
-FROM alpine:3.15
+FROM alpine:3.20
 
 RUN apk add --no-cache \
     blkid \

deploy/docker-swarm/pkg/Dockerfile

@@ -11,7 +11,7 @@ RUN ls -al
 ARG CGO_ENABLED=0
 RUN go build -o aio.bin github.com/hetznercloud/csi-driver/cmd/aio
 
-FROM --platform=$TARGETPLATFORM alpine:3.15
+FROM --platform=$TARGETPLATFORM alpine:3.20
 
 RUN apk add --no-cache \
     blkid \

dev/Dockerfile

@@ -17,7 +17,7 @@ ARG SKAFFOLD_GO_GCFLAGS
 RUN go build -gcflags="$SKAFFOLD_GO_GCFLAGS" -o controller.bin github.com/hetznercloud/csi-driver/cmd/controller
 RUN go build -gcflags="$SKAFFOLD_GO_GCFLAGS" -o node.bin github.com/hetznercloud/csi-driver/cmd/node
 
-FROM alpine:3.15
+FROM alpine:3.20
 
 RUN apk add --no-cache \
     blkid \