Alpine DockerStatic Dockerfiles fail on GPG verification step

From trying to create the alpine containers on my local machine:
```
STEP 8/27: RUN wget -q `curl -s 'https://api.adoptium.net/v3/assets/feature_releases/21/ga?architecture=x64&heap_size=normal&image_type=jdk&jvm_impl=hotspot&os=alpine-linux&page=0&page_size=1&project=jdk&vendor=eclipse' | grep signature_link | awk '{split($0,a,"\""); print a[4]}'` -O /tmp/jdk21.sig
--> e02b84003212
STEP 9/27: RUN gpg --verify /tmp/jdk21.sig /tmp/jdk21.tar.gz
gpg: Signature made Wed Oct 22 00:23:16 2025 UTC
gpg: using RSA key 3B04D753C9050D9A5D343F39843C48A565F8F04B
gpg: Note: database_open 134217901 waiting for lock (held by 6) ...
gpg: Note: database_open 134217901 waiting for lock (held by 6) ...
gpg: Note: database_open 134217901 waiting for lock (held by 6) ...
gpg: Note: database_open 134217901 waiting for lock (held by 6) ...
gpg: Note: database_open 134217901 waiting for lock (held by 6) ...
gpg: keydb_search failed: Operation timed out
gpg: Note: database_open 134217901 waiting for lock (held by 6) ...
gpg: Note: database_open 134217901 waiting for lock (held by 6) ...
gpg: Note: database_open 134217901 waiting for lock (held by 6) ...
gpg: Note: database_open 134217901 waiting for lock (held by 6) ...
gpg: Note: database_open 134217901 waiting for lock (held by 6) ...
gpg: keydb_search failed: Operation timed out
gpg: Can't check signature: No public key
Error: building at STEP "RUN gpg --verify /tmp/jdk21.sig /tmp/jdk21.tar.gz": while running runtime: exit status 2
```
Not sure if this affects other platforms - I was trying Alpine in order to replicate a specific test failure on my local Fedora 42 host system.

Start with the Alpine DockerStatic Dockerfiles and reproduce the failing build through the `gpg --verify` step shown in the report. Trace the key setup and signature-download steps, then confirm that the Alpine image builds successfully with the JDK signature verified.

Written by the indexing model from the issue text.