solana: Bump Solana CLI version to 1.18.26 (wormhole-foundation#599)

Current Solana CLI version (`1.18.10`) is not [officially supported](https://github.com/anza-xyz/agave/releases/tag/v1.18.10).
This PR bumps the Solana CLI version (and associated deps) to `1.18.26` - [last stable release before v2](https://github.com/anza-xyz/agave/releases/tag/v1.18.26).

Author: nvsriram

.github/workflows/solana.yml

@@ -99,7 +99,7 @@ jobs:
       - uses: metadaoproject/setup-anchor@v2
         with:
           node-version: "20.11.0"
-          solana-cli-version: "1.18.10"
+          solana-cli-version: "1.18.26"
           anchor-version: "0.29.0"
       - name: Cache node_modules
         uses: actions/cache@v3

solana/Anchor.toml

@@ -1,6 +1,6 @@
 [toolchain]
 anchor_version = "0.29.0"
-solana_version = "1.18.10"
+solana_version = "1.18.26"
 
 [features]
 seeds = false