deps: revert downgrade grpc to 1.67.1 #2366 (#2414)

Change-Id: I13f78d94d3f1e775e24168c7f3c1cabd9a96d6d1

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Fixes #<issue_number_goes_here> ☕️

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Author: igorbernstein2

google-cloud-bigtable-deps-bom/pom.xml

@@ -63,16 +63,6 @@
 
   <dependencyManagement>
     <dependencies>
-      <!-- Temporarily downgrade grpc version since 1.68.0 was a mistake:
-      https://github.com/grpc/grpc-java/releases/tag/v1.68.0 -->
-      <dependency>
-        <groupId>io.grpc</groupId>
-        <artifactId>grpc-bom</artifactId>
-        <version>1.67.1</version>
-        <type>pom</type>
-        <scope>import</scope>
-      </dependency>
-
       <!-- google cloud boms -->
       <dependency>
         <groupId>com.google.cloud</groupId>