Revert protobuf upgrade for Android compatibility

protobuf-java 4.32.1 generates bytecode that AGP 7.4.2's D8 dexer
cannot process (IdentifyOuterClass and similar generated classes fail
to dex). Reverting to 3.25.5 (the current develop version) restores
Android compatibility.

protobuf 4.x can be revisited once AGP is upgraded (tracked in libp2p#458).

Author: lucassaldanha

libp2p/build.gradle.kts

@@ -1,5 +1,5 @@
 plugins {
-    id("com.google.protobuf").version("0.9.5")
+    id("com.google.protobuf").version("0.9.4")
     id("me.champeau.jmh").version("0.7.3")
 }
 

versions.gradle

@@ -27,7 +27,7 @@ dependencyManagement {
         dependency "io.mockk:mockk:1.13.3"
         dependency "org.assertj:assertj-core:3.27.4"
 
-        dependencySet(group: "com.google.protobuf", version: "4.32.1") {
+        dependencySet(group: "com.google.protobuf", version: "3.25.5") {
             entry 'protobuf-java'
             entry 'protoc'
         }