Report concrete versions for floating Oracle JDK downloads (#1213)

* Fix floating Oracle JDK version resolution

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

* Update generated distribution bundles

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

* Harden floating artifact cache identity

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

* Regenerate setup bundle after cache hardening

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

* Temporarily enable hosted full validation

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

* Export hosted formatting results

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

* Apply repository formatting

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

* Run hosted validation after formatting

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

* Correct floating version regression tests

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

* Remove temporary validation wiring

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

* Cache checksum-less floating artifacts by their response fingerprint

Oracle and Oracle GraalVM do not always publish a `.sha256` sibling next
to a `/latest/` artifact. Those floating releases were excluded from both
the resolution cache and the JDK cache, so `cache-jdk` users lost caching
entirely for them.

A floating URL is a constant string, so it cannot serve as a cache
identity on its own — a stale entry would be reused forever. Instead,
derive a validator from the headers of the HEAD request that already
resolves the artifact: the ETag when present, otherwise `Last-Modified`
combined with `Content-Length`. Republishing changes the validator, which
changes the cache key, so a new build is downloaded rather than masked.

`getJdkReleaseIdentity` now falls back to that fingerprint before the
URL, and the floating cache gates ask whether the release has a stable
identity (checksum or fingerprint) rather than a checksum specifically. A
floating release with neither is still left uncached.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Co-authored-by: Bruno Borges <brborges@microsoft.com>

__tests__/verify-java.sh

@@ -12,6 +12,8 @@ fi
 
 EXPECTED_JAVA_VERSION=$1
 EXPECTED_PATH=$2
+SETUP_JAVA_VERSION=$3
+REQUIRE_CONCRETE_VERSION=$4
 
 EXPECTED_JAVA_VERSION=$(echo $EXPECTED_JAVA_VERSION | cut -d'+' -f1)
 if [[ $EXPECTED_JAVA_VERSION == 8 ]] || [[ $EXPECTED_JAVA_VERSION == 8.* ]]; then
@@ -31,6 +33,21 @@ if [ -z "$GREP_RESULT" ]; then
   exit 1
 fi
 
+if [ -n "$SETUP_JAVA_VERSION" ]; then
+  OUTPUT_JAVA_VERSION=$(echo "$SETUP_JAVA_VERSION" | cut -d'+' -f1)
+  OUTPUT_GREP_RESULT=$(echo "$ACTUAL_JAVA_VERSION" | grep -E "^(openjdk|java) version \"$OUTPUT_JAVA_VERSION")
+  if [ -z "$OUTPUT_GREP_RESULT" ]; then
+    echo "::error::The version output does not match the installed Java version"
+    echo "Version output: $SETUP_JAVA_VERSION"
+    exit 1
+  fi
+  if [ "$REQUIRE_CONCRETE_VERSION" = "true" ] && [ "$OUTPUT_JAVA_VERSION" = "$EXPECTED_JAVA_VERSION" ]; then
+    echo "::error::Expected a concrete version output for a floating JDK"
+    echo "Version output: $SETUP_JAVA_VERSION"
+    exit 1
+  fi
+fi
+
 if [ "$EXPECTED_PATH" != "$JAVA_HOME" ]; then
   echo "::error::Unexpected path"
   echo "Actual path: $JAVA_HOME"